For more than 20 years, Don Miller has fought for civil rights, open housing, gay liberation. Now Miller has AIDS, and he is fighting for the right to die and be buried in the manner he chooses.

Miller, 50, has not planned his funeral. On the contrary, the Baltimore man said his crusade to open an AIDS hospice and to persuade local funeral homes to provide full services to victims of acquired immune deficiency syndrome keeps him "fired up" and prevents him from brooding about death. In the struggle to live with AIDS, Miller clings to his causes to keep illness and despair at bay.

The fervor that impels him to campaign for AIDS victims' rights has prompted him to speak openly about his illness with acquaintances, co-workers and reporters. Miller says he wants to dispel the notion that everyone with AIDS is emaciated and near death. He has had the disease for three years, and he continues to work almost full-time at Baltimore Neighborhoods Inc., a nonprofit civil rights agency.

"People say I look healthy," he said, leaning across a cluttered desk in his third-floor office in central Baltimore. His skin was ruddy, and a few moments earlier he had taken the two flights of stairs briskly, without breathing hard. "Right now it happens . . . I'm not that sick, I can still get around, I can still do some things. I'm going to fight like hell."

Yet, he said living with AIDS has been an encounter with loneliness, rejection and uncertainty, increasing financial worries and the ever-present fear that his luck -- the luck of belonging to the group of AIDS patients with the mildest symptoms -- will run out.

Co-workers at his job of 19 years have accepted his illness calmly, but many of his closest friends have begun avoiding him. "Some of that might be my fault, since I've never been much socially," he said. "But . . . there's been a handful of people who've always been in and out of my life, who have always been close and friendly. That doesn't seem to be there now."

AIDS has become the focus of Miller's activism. In April 1985, at a friend's suggestion, he called three Baltimore-area funeral homes to ask what services were available for victims of the disease. He had his own funeral in mind, but when the first two homes said they would not handle the body of an AIDS victim and the third refused to allow an open casket, Miller was incensed. With the help of two volunteers, he surveyed all the funeral homes in the Baltimore area.

"From the 98 that were actually contacted, 56 indicated some form of discrimination," either refusing to receive AIDS victims, refusing to embalm them or prohibiting services and open caskets, he said.

Some funeral home workers in Baltimore and other cities have been reluctant to handle the bodies of AIDS victims, particularly to embalm them, because of fear of acquiring the disease through contact with blood or body secretions.

Miller said a national organization for funeral directors said last year that morticians need not fear catching AIDS as long as they take a few simple precautions.

Miller filed a complaint last November with the Maryland State Board of Morticians, which prompted an investigation by the state attorney general's office. He said that on May 23, he received a letter from the Board of Morticians stating that it had considered his complaint and the investigator's report, and had decided to take no action. The board also refused to let him see the report, citing a law that protects confidentiality of licensing records.

Miller said he will seek further legal remedies. On the day the letter arrived, an elderly woman whose son was dying of AIDS called him seeking help in finding a funeral home that would provide services. "It just again struck to my core," he said. He said he has put off planning his own funeral until the issue is resolved, adding, "Now I feel quite obliged to have an open casket just to make a point."

He is also leading a campaign to establish a Baltimore hospice where AIDS patients too sick to stay at home could be cared for until death. He is co-chairman of a committee of the AIDS Interfaith Network, a religious organization that reported in April that four of Baltimore's nine hospice programs are not open to AIDS victims.

The committee found that only one Baltimore hospital, St. Agnes, had admitted AIDS patients to an in-hospital hospice program. Three others said they were willing to take AIDS patients but had not done so. A fifth program, operated by the Visiting Nurses Association, had provided home care to 35 terminally ill AIDS patients.

Miller said that since the report was published, Archbishop William Borders of Baltimore has promised to work with him and other religious leaders to establish a separate AIDS hospice.

Since he learned he had AIDS in June 1983, Miller has been troubled mainly by Kaposi's sarcoma, a cancer common in AIDS patients, which has been controlled by radiation and chemotherapy. His hope is to stay well enough to keep working, to care for a roommate who was diagnosed with AIDS last month and to stay in his adopted city, where his involvement in church and political causes is dearer than friends.

His fear is that he may begin to develop infections serious enough to force him to quit his job and lose financial independence. He has seen it happen to others.

"When you deal with people who are really sick and . . . at the mercy of the system, they end up a ward of the state or of the federal government," he said. "I just feel once you get into that situation, people treat you even worse."

Miller's physician, Richard D. Leavitt of the University of Maryland Cancer Center, said Miller's medical case is not unusual among AIDS victims, but his ability to handle the psychological burden stands out.

"To look at this disease as a positive short-term death sentence is not accurate," he said. Real illnesses "just aren't like 'Love Story,' where a person is well one day and the next day just goes to sleep. Real illness is ups and downs, emotional stresses, good times and bad times . . . . You wonder where anyone gets the reserve to just cope, and then when you see somebody who not only copes but thrives . . . I, at least, am overwhelmed."

Yet, Leavitt said both he and Miller know that Miller's strength will fail sooner or later. "We can't give it a number," he said. "Eventually, Don will die from AIDS, either from an advanced cancer . . . a second cancer, or from an opportunistic infection. Whether that will happen next week, next month or a year from now, I don't know."

Figures on AIDS survival suggest Miller has already beaten the odds. In a 1984 study of more than 1,000 such patients, those with Kaposi's sarcoma alone did best, surviving an average of 125 weeks after diagnosis. For patients with Kaposi's sarcoma plus infections with pneumocystis or other unusual organisms seen in AIDS, the average survival period fell to 65 or fewer weeks. The group of patients who had infections but did not have Kaposi's sarcoma or pneumocystis pneumonia survived, on the average, only 18 weeks.

Surviving AIDS for three years is unusual enough that the federal Centers for Disease Control is beginning a study of more than 300 reported AIDS patients who were diagnosed more than three years ago, to ascertain whether all of them really have the disease. "We may find some subset of people who truly do have AIDS, who truly have survived for that period of time," said Dr. Tom Starcher, a public health adviser with the CDC's AIDS program.

Leavitt talks to Miller frequently by telephone and examines him about once a month. Miller has been hospitalized twice for leg infections but is reluctant to have further radiation therapy for his Kaposi's sarcoma, which now involves both legs. He tries to wait out colds or fevers without calling the doctor, preferring to avoid hospitals when he can.

Miller learned in June 1983 that he had the disease during a telephone call from a dermatologist who took a biopsy of a "blister" and found Kaposi's sarcoma. He decided immediately to tell family and friends and to work to educate others about AIDS. That seemed a logical extension of his involvement in the Roman Catholic church and the gay rights movement.

"My individual focus all along -- my whole life, actually -- has been my gayness and my faith, and I don't see it as two sides of a coin," he said. "It's part of me. It is me."

He discovered he had AIDS on a Friday. On Monday morning he informed his boss, George B. Laurent, associate director of Baltimore Neighborhoods Inc., and within a week or two everyone on the 13-member staff learned of it.

"We made no fuss," Laurent recalled. "Nobody was apprehensive . . . . We're civil rights people. We've faced all these phobias before."

When Miller is not buoyed by the excitement of a cause, the emotional strain of his illness wears him down. He said he has known he was gay since adolescence, adding that he was "a high-risk person," with frequent sexual encounters, before contracting AIDS. He has no idea who gave it to him.

"Once I was diagnosed, I didn't notice any physical difference in me at all. But yet . . . I started pulling back right away" from other people, he said. "I started to devote more time to personal things . . . and as time went on, there was the tiredness."

Fatigue began to interfere with his work, and he felt guilty. "You're torn . . . because there's more urgency to your activism and yet, physically . . . you need your sleep now and you have to watch out for these infections that can crop up," he said.

Even responding to others' concern is a strain. "You have to fight sort of at every level," he said. "People have good intentions, but they will come with their latest recipes or latest diets . . . . You get that kind of constant advice. Others . . . are reminding you that you might be sick, because they say they're praying for your recovery.

"You're constantly battling all this kind of attention . . . . You just want to be normal, you just want to be average, and yet you need somebody to be supportive."

Despite acquaintances' show of support, Miller said many of his closest friends are keeping their distance. A young lawyer whom he used to see often has stopped calling. Another friend avoids mentioning Miller's illness, even though Miller is sure he knows. He said many gays seem reluctant to be in the same room with someone who has AIDS. "There's more and more of that isolation from people outside of the issue," he said.

Kaposi's sarcoma has spread to both feet and may have spread elsewhere. Kaposi's sarcoma is a cancer of blood vessels and connective tissue that usually appears as purplish spots or nodules in the skin, most often starting on the legs or arms. It can spread to skin on other areas of the body and to internal organs.

At times he is uncertain whether pain in his feet and fingers is from the tumor or from some action of the AIDS virus on nerves. He also is unsure whether to blame his moodiness on the psychological stress of the disease or the virus's poorly understood effects on the brain.

"I've always been kind of a crazy person -- comical, silly, if you will," he said. "At times now, I'm really serious, and people say, 'What's wrong ?' "

Miller said his religion and social activism have been his greatest sources of strength. Raised by a Catholic aunt and uncle in St. Paul, Minn., he spent several years studying to enter the priesthood. Later he switched to civil rights work, first in Kansas City, then in Baltimore.

Father Frank Callahan, pastor of Corpus Christi Church where Miller is a member, said the only time he has seen Miller despondent was the afternoon he learned he had AIDS. "I bet you within 24 hours he was out of that," he said. "I've never seen him back in that frame of mind again."

Callahan recalled the Thursday in April when Miller came from the hospital, where he had undergone a lung biopsy, to attend a service commemorating Jesus' last supper before his death. At one point, church members were invited to wash one another's feet in memory of a similar action Jesus performed for his disciples.

"I felt really impelled to do it, so I went and washed his feet," Callahan said. Then Miller approached another man, "a friend who had abandoned him, and he took him up and took his shoe off and washed his foot."

It was a gesture "of reconciliation, of peace, of strength. Great strength," Callahan said.