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A somber Princess Diana tells of a lonely and desperate existence in her early married life to Prince Charles, saying in interviews recorded by her biographer that she "had tremendous hope in me which was slashed by day two."

In audiotapes broadcast Thursday in a two-part NBC News special, The Princess of Wales described her early knowledge of Prince Charles' affair with Camilla Parker Bowles (search), her battle with bulimia, and several suicide attempts.

"I threw myself down the stairs bearing in mind I was carrying a child," she said, describing one incident. "Queen [Elizabeth] comes out, absolutely horrified, shaking she's so frightened ... and Charles went out riding."

The princess died at age 36 in a 1997 auto accident in Paris.

In the interviews, she described how sad she was in her relationship with Prince Charles.

"My husband made me feel so inadequate in every possible way," she told her biographer Andrew Morton (search). "Every time I tried to come up for air, he pushed me back down again."

NBC wouldn't say how much it paid author Morton's publisher for the tapes, which served as the basis of the special, "Princess Diana: The Secret Tapes."

In one recording, Diana told of overhearing a phone conversation Charles had with Parker Bowles.

"I once heard him on the telephone in his bath ... and he said, 'Whatever happens, I'll always love you,'" the princess said. "And I told him I'd listened at the door ... we had a filthy row."

She later said her eating disorder "started the week after we got engaged."

"My husband put his hand on my waistline and said: 'Oh, a bit chubby here, aren't we?' And that triggered off something in me," Diana said.

When Morton's book, "Diana: Her True Story" was published in 1992, it punctured the fairytale fantasy so many royalty fans had cherished. At the time, Diana did not acknowledge being the source of it.

The book, detailing an unhappy marriage to Prince Charles and his close relationship with Bowles, angered her family, the royal family, and many friends.

But when Morton published a revised version barely a month after Diana's death, he said the princess was the source of the original version.

There were few, if any, revelations in 1997's "Diana, Her True Story — In Her Own Words."

But Morton included a 46-page transcript of words he said were all Diana's except for some in parentheses. He said they substantiated everything he had written previously about her.

Diana had cooperated with the book "fully and frankly and consistently over an eight, nine-month period of time," he said.

Morton said he obtained the taped comments from the princess by using a go-between who conducted the interviews but wanted to keep his identity secret.

Within days, however, the book's publisher Michael O'Mara issued a statement saying Dr. James Colthurst (search), a longtime friend of Princess Diana, had taped her interviews, which total about five hours.

NBC used mostly stock footage of Diana to illustrate its special. But in next week's second part, it will use never-before-seen footage purchased from Diana's former speech coach of her practicing speeches.

NBC has acknowledged that the tapes provide no new revelations, but the network believes it will be illuminating to viewers to hear Diana's own voice.