Lynda Van Devanter went to Vietnam as an Army nurse in l969, a nice Catholic girl from Arlington who sported a rhinestone American flag pin in the lapel of her fatigues. She came home a year later bitterly opposed to the war, and spent the next decade in a numbing swirl of unrewarding jobs and failed relationships, drinking herself to sleep and vainly trying to banish the recurring nightmare of a dying teen-age soldier whose face had been blown off.

Van Devanter's painful metamorphosis is graphically chronicled in her autobiography "Home Before Morning," the first account of the war by a woman veteran. The book, published last month and now in its second printing, has sparked an emotional debate among female soldiers, a group that has been largely overlooked in the national reexamination of America's longest and most unpopular war.

Although the controversy echoes earlier debates about Vietnam books written by male veterans, it is tinged with the particular sensitivity that surrounds questions involving women in the military. Only 7,000 of the 2.8 million Vietnam veterans are women, most of them nurses like Van Devanter.

Critics, among them several Army officers who served with Van Devanter at the 67th and 71st Evacuation Hospitals, are disputing portions of the book, saying she has exaggerated and distorted conditions to bolster her anti-military political views. A high-ranking official of the Veterans Administration claims Van Devanter's explicit portrayal of wartime relationships--including a long affair with a married surgeon--the use of profanity, the heavy drinking and drug use she describes, as well as her post-war breakdown cast "the entire Army nurse corps in a disparaging light."

"Lynda Van Devanter herself has said on numerous occasions that the image of the Army nurse is either lesbian or whore," said Nora Kinzer, special assistant to VA Administrator Harry Walters, who challenged the book on a local TV talk show broadcast yesterday. "I am upset that such an image is portrayed in her book," said Kinzer, a former assistant secretary of the Army who notes that the VA is eager to present all Vietnam veterans in a "positive light."

Van Devanter, women's director of the Washington-based Vietnam Veterans of America (VVA), denies that she distorted conditions. She attributes much of the criticism to her book's frankly anti-military tone and to her political activism, including a highly publicized trip to Hanoi by a veteran delegation last Memorial Day that angered some conservatives.

"This is my story although many others had similar experiences," said Van Devanter, 36, during an interview in her office in the rundown Capitol Hill town house that serves as VVA headquarters. "These people would obviously prefer that I had written a book that said we were saints and angels and everything was wonderful," said Van Devanter. "They're trying to write revisionist history."

That is precisely what several of Van Devanter's former colleagues say she has done.

The book is replete with vivid descriptions of grueling 72-hour shifts by medical personnel "falling into an almost deathlike sleep at the operating tables." It says they worked under a steady barrage of enemy rocket attacks on a "never-ending flow of casualties," while standing in an inch-deep mixture of mud and blood "reminiscent of a '50s horror film."

"I certainly don't recognize that," said Col. Mary Grace, who was a nursing supervisor at the 71st Evacuation Hospital near Pleiku, where Van Devanter worked as an operating room nurse from June 1969 to March 1970. "I'd say she's been watching too much 'M*A*S*H,' "said Grace, now chief nurse at an Army hospital in Fort Bragg, N.C.

"Lynda's exaggerations and the negativism of her book distress me terribly," said retired Col. Edith Knox of Burke, former head nurse of the 67th Evacuation Hospital in Qui Nhon. "This book makes us look like a bunch of bed-hopping, foul-mouthed tramps."

Jo Ann Webb of Arlington, a former Army nurse, said Van Devanter "fictionalized" the workload and should have used real names in the book. (All names except those of Van Devanter and her immediate family have been changed.)

"She talks about this endless flow of casualties and official Army figures show the hospital was only 50 percent full," said Webb. "I'm incensed that she's become a professional veteran and now she's making money off it." Webb's husband is author James Webb, the former minority counsel to the House Committee on Veterans Affairs and a highly decorated Marine captain who wrote the best-selling Vietnam novel, "Fields of Fire."

The criticism is fueled by the apparent commercial success of Van Devanter's book. The paperback rights have just been sold for more than $100,000. The Hollywood production company that produced "A Case of Rape" and other television movies has bought an option on the book, signed Van Devanter as a consultant and is scouting for actresses--Sally Field and Elizabeth McGovern have been mentioned--to star in a possible film.

Van Devanter, who earns $12,000 annually, says she plans to turn over half of what she earns from the book to the VVA. She wrote the book, she says, because she wanted to reassure other female vets disturbed by Vietnam memories "that they're not alone, and they're not crazy. I certainly didn't do it for the money."

"It's absolute bull---- for Jo Ann Webb to spout these figures, which don't tell you anything about the magnitude of the casualties," said Van Devanter. "This is not a book about numbers."

"This is also not a big sex book," she continued, angrily stabbing out a cigarette. "I mentioned exactly two relationships in Vietnam, both of which illustrated the need to hold onto another human being in a situation of complete insanity. And I can't believe Jo Ann Webb would say I should have used real names. Imagine being 12 years down the road and finding out in a book that your husband had an affair with someone in Vietnam."

Van Devanter's descriptions of Vietnam are substantiated by other women veterans, including her former roommate, Army nurse Lynn Calmes Kohl. "Actually what Lynda wrote was mild," said Kohl, now a housewife in Appleton, Wis., who like Van Devanter, suffered a breakdown after the war. "I think very few people even realize that women were in Vietnam and I think a lot of them would like to keep it that way. It was like 'M*A*S*H.' "

Van Devanter, the second of five daughters of a career federal bureaucrat, had never lived further away than Baltimore when she was shipped to Vietnam, a 22-year-old "superpatriot" who wanted to help people and dreamed of returning home to a life in the Virginia suburbs complete with a wood-paneled station wagon.

She returned home at 23, full of loathing for the war and anger at the Army, lived briefly in Alexandria, moved to Los Angeles and then back to Washington. She lost a series of nursing jobs, frequented singles bars in a desperate search for companionship, and haunted by wartime memories, drank heavily and suffered bouts of depression so severe she cried for weeks. She went on welfare, married and divorced and finally discovered through a counselor who specialized in veterans' problems that she was suffering from post-traumatic stress disorder, a condition that affects an estimated 700,000 male veterans.

Van Devanter began writing the book in 1979 as therapy. Two years and two drafts later she hired a professional freelance writer, co-author Christopher Morgan. "I had terrible amnesia about major portions of time," Van Devanter recalled, "so we spent days sitting in my living room with the tape recorder. He would prod me constantly, asking 'What were you holding?' 'What were you wearing?' Sometimes I just hated him, but he made me remember."

"The first publisher told me no one wanted to read about women at war," she said. "But now I think people are more willing to talk about it."