They talk of migraines and mortgages, shattered dreams and sleepless nights, boredom and bedlam, high blood pressure and low morale.

Anxiety has been building -- some election day -- among federal employes in agencies the Reagan administration has targeted for dissolution or major cuts. Last week's assassination attempt, some predict, may confirm their worst fears.

"Reagan came off like John Wayne," says Greg Kenefick, spokesman for the American Federation of Government Employes (AFGE). "It makes it hard to be a critic of his proposals."

The Senate last week approved $36.9 billion worth of Reagan's budget cuts for next year. And now, as the proposals are being debated in the House, thousands of civil servants are wondering whether they'll be employed come September.

On everyone's lips -- as nagging as the ominous background music in "Jaws " -- are three little letters, RIF. An acronym for reductions-in-force, a RIF is the complicated procedure for deciding which employes get paychecks and which their walking papers.

The size of the coming RIF is not yet known, and most federal officials think it will be August before any major lay-offs are made. But agencies are working up RIF plans in case they must make cuts that cannot be met by attrition.

Administration officials say attrition will account for the bulk of the 63,000 non-defense job cuts they predict by 1982. However AFGE -- the largest union representing federal employes -- calls this figure "unrealistic," and claims attrition won't account for even half the 100,000 jobs they estimate will be abolished over the next two years.

What everyone does agree on, is that no one really knows exactly what will happen. So for now, employes at agencies on the "hit list" (most of whom are paranoid enough they don't want their names used) must cope with the anxieties and terror of waiting for The Grim RIFfer.

"The mood among federal workers?" chortles one such employee, in a voice somewhere between terror and hilarity. "It's like a funeral home here, except all the dead bodies are still walking around,"

"There's a very real -- almost tangible -- fear here," says Kay Henry, 44, a program specialist at the Department of Education and president of AFGE Local 2607.

"The big problem is in dealing with a lot of unknowns. We don't have any solid information on what top management is going to do, and we don't know if we'll be around much longer.

"But people are sending their kids through school and have other bills to pay, so they're trying to make decisions about their lives and careers. It's very stressful and more than a little frightening."

In this vacuum of uncertainty, the rumor mill often runs wild. Paranoia over the possibility of being placed on an agency's "RIF list" has led to what one federal worker calls "an epidemic of Riffer Madness."

"There's a RIF mentality' in operation here," says an HHS psychologist. "All of a sudden people are counting their years of service, looking at their grade level and guessing which of their co-workers are veterans (who get special preference under RIF rules). Your colleagues become your enemies, because it can come down to you or him .

"People are watching programs they've put their hearts and sweat into being cut and abolished. They're walking around in shock. Some people are very lethargic -- a classic depression symptom. A lot of people are just sitting around reading newspapers, because they don't have any more work to do. It's pretty grim."

"The desperation is worst," says a Commerce Department employee, "among people in their 40s and 50s with 10 to 20 years service, married with kids. They're wondering what to do, where to turn, how to survive."

Similar conditions prevail at other agencies on the "endangered species" list. Common sights, some report, are long lines at the office health center (frequently from new victims of high blood pressure) and phoney "gallows humor" memos.

"There's a sort of hysterical hilarity here," says a 27-year-old program analyst for the Department of Energy, "I think because people are in shock. We've been bringing in cakes every day and going out on shopping sprees.

"My husbank works here, too, so we both may be out of jobs. But I've spent $500 on clothes in the past two weeks. I tell myself I need interview suits, but deep down I think it's a way to keep up my spirits.

"We're a close group where I work, and we've semi-seriously thought of placing a classified ad for a 'Branch for Hire.' If someone goes job hunting we call him a traitor. It's like rats leaving a sinking ship, or being a character in an absurdist play."

The "big joke" at the Community Services Administration, says an 11-year agency veteran, "is that we're trying to keep people off the dole, but we may wind up on it.

"There's a high level of frustration, with everybody wondering what's going to become of them. There's a lot of busywork going on, and we've got GS-15s and -16s twiddling their thumbs, waiting for the axe to fall."

Part of this frustration at agencies like CSA -- which has been named for dissolution -- is philosophical.

"It's a source of sadness," reflects public information officer John Macomber, 66, who joined CSA in 1965 when it was created as the Office of Economic Opportunity -- part of The Great Society's War on Poverty.

"I developed the feeling that what we were trying to do was right, and I still have that feeling. It's sad it has to end this way. I had wanted to work until I had to stop, but now I'm going to sell my home, move to the Outer Banks (in North Carolina) and fish."

Others are not so fortunate.

"A very close friend of mine is 60 years old with only 13 years of service," Macomber says. "With 25 years experience as a reporter and editor, he's going to have to compete in a tight job market with ambitious journalists in their 20s and 30s."

There are some "plans in the works," he says, to assist the 1,000 CSA employes "in becoming located in other federal jobs as they become available. But I don't know yet what that means, or how effective it will be."

At HHS, some employes are trying to ensure that they won't be left out in the cold. "My agency held an employe briefing on RIF procedures," says an HHS staffer, "and a couple of us stood up and wanted to know what we could do. Most of us are from the activist '60s and questioned whether we had to just sit and take this."

These employes formed a self-help group and have sent out a questionnaire to see what information and services employes need. "We want to help people learn their rights, get counseling and job placement," says one of the organizers. "As for me, I've got a program that I believe in to run. They're going to have to drag me out of here."

This dedication to continue working is not uncommon, and some workers also voice resentment towards a public who views them as "do-nothing bureaucrats."

"When Chrysler failed they blamed the management," notes a Department of Energy staffer. "But when the government fails, they fault the worker."

In contrast, there are some federal workers voicing positive attitudes about the proposed cuts. "I don't think it will be hard for me to get a job." says secretary Nancy Creel, 32, of the Economic Development Administration -- which has been targeted for dissolution. "Maybe I can make this an opportunity to enter a different type of career.

"I'm very positive about Reagan and what He's doing. So I'm willing to sit back and maybe suffer a little bit. Sometimes there has to be a little pain before the gain."

Others remain optimistic that their agencies will not die.

"I'm not taking a defeatest attitude," says Gene Kaufman, 54, a division chief at EDA. "While I still have a job to do, I'll do it the best I can."

"There are still worthwhile things to do," adds EDA's Ed Levy, 27. "I'd hate to leave here, but I always have my cab driver's license to fall back on."

Women and minorities will be among the hardest hit by RIFs, says Mae Walterhouse, 52, of EPA and past national president of Federally Employed Women.

"Seniority and veteran's preference are the pillars of a RIF," she notes. "Women are among the last hired and are not likely to be veterans. We're proud that we here at EPA have the highest average grade for women. But now that may go down the tubes and we're wondering, 'Was it all for naught?'"

The cutbacks' effect on those employed by federal programs like CETA (the Comprehensive Employment Training Act)?

"We're at least safe through June," says Beverly Lee Reid, director of the in-school CETA program for Fairfax County Public Schools, which provides job training and experience for about 350 students per year. "And we're probably okay through September. But after that, who knows?"

After November's election, Reid began getting concerned phone calls from students in her programs. By January the number of calls increased, she says, and the tone became frantic.

"In the last month," Reid says, "the mood has shifted from fear to panic to terror. Some of these kids are supporting unemployed parents, and their salaries are keeping their families together. I've got 10th graders whose check makes the difference in their eating or not.

"It's very depressing, because this program gives hope to people who otherwise don't have much hope. Their future depends, a great deal, on this training. Some of the kids blame themselves, wondering, 'What did I do wrong to lose my job?' They feel powerless."

Reid admits she and her staff share some of these feelings because their jobs may be on the line, too.

"But we're sacrificing our own concerns in favor of what we can do for the students. Hopefully, we'll be absorbed by the system. We all have degrees and experience that will count somewhere else. Right now we're just trying to make the most of the time we have left."