Washington ? Hillary Rodham Clinton, acknowledging tirades and tears over her husband’s affair with Monica Lewinsky, says former President Clinton lied to her about the relationship until the weekend before he admitted as much to a grand jury.

The New York senator vividly describes her pain about the betrayal in “Living History,” her new memoir covering her eight years in the White House. The book goes on sale Monday.

“The most difficult decisions I have made in my life were to stay married to Bill and to run for the Senate from New York,” she writes.

She says she accepted her husband’s story at first — that he had befriended the White House intern when she asked for job-hunting help, “had talked to her a few times” — and that the relationship had been horribly misconstrued.

“For me, the Lewinsky imbroglio seemed like just another vicious scandal manufactured by political opponents.”

More than six months later, with the president preparing to testify before a grand jury, Mrs. Clinton was still adamant that her husband had done nothing wrong and was the victim of a “vast right-wing conspiracy.”

Then, on the morning of Saturday, Aug. 15, 1998, he woke her up, paced at the bedside, and “told me for the first time that the situation was much more serious than he had previously acknowledged.”

“He now realized he would have to testify that there had been an inappropriate intimacy. He told me that what happened between them had been brief and sporadic.”

He was ashamed and knew she would be angry, she recounts.

“I could hardly breathe. Gulping for air, I started crying and yelling at him, ‘What do you mean? What are you saying? Why did you lie to me?’ I was furious and getting more so by the second. He just stood there saying over and over again, ‘I’m sorry. I’m so sorry. I was trying to protect you and Chelsea.”‘

Mrs. Clinton said that up until that August morning when her husband confessed, she believed he was being railroaded and had merely been foolish by paying any attention to Lewinsky. She was incredulous that he would endanger their marriage and family.

“I was dumbfounded, heartbroken and outraged that I’d believed him at all.”

She said the president’s eyes filled with tears when she told him he would have to confess to their teenage daughter as well.

She ultimately decided she still loved her husband, although “as a wife, I wanted to wring Bill’s neck.”

She describes in bitter terms the months of chill between them, never more painful than when they went to Martha’s Vineyard for vacation right after his testimony.

“Buddy, the dog, came along to keep Bill company. He was the only member of our family who was still willing to.”

While on the island, she felt “nothing but profound sadness, disappointment and unresolved anger. I could barely speak to Bill, and when I did, it was a tirade. I read. I walked on the beach. He slept downstairs. I slept upstairs.”

She said her decision to run for a Senate seat from New York provided a healing bridge for them. “Bill and I were talking again about matters other than the future of our relationship. Over time we both began to relax.”

She was the first first lady to run for elected office, defeating the Republican candidate, former Rep. Rick Lazio, in 2000. She was sworn into the Senate the same month her husband left office in January 2001. She recounted their last day at the White House, waltzing down a hallway in her husband’s arms.

She concludes that what her husband did was morally wrong but not a betrayal of the public.