For a woman who admits that her young daughter once stumbled across Mommy using heroin, drawing more attention to the couple's marital mess might seem an odd strategy. O'Neal acknowledges this and admits that publicizing the tape's contents "is kind of exploitative." Still, she says, "I have to protect what dignity and truth is mine." McEnroe, in a statement to PEOPLE, responded that "I am very disappointed in Tatum's statements. I had hoped that after all these years she would see things more accurately and that she would share my concern for the welfare of our children."

Now, after a half-dozen stints in rehab, O'Neal claims that she has crashed-and-burned for the last time. Prior to her most recent coke binge, "I kept hearing a voice in my head say, 'You're a coward. I hate you. Your kids hate you. You're not worth a thing, Tatum,' " she recalls. For now, she insists, she has prevailed: She says she has been clean for three months. Describing herself as "one strong bitch," she says, "I have this gnarly inner strength."

It has certainly been tested. Tatum was 2 when her parents -- Ryan and actress Joanna Moore, who had met on the 1960s TV show The Virginian -- divorced. While Ryan continued to pursue a career in Hollywood, Tatum and Griffin lived in "a really dilapidated house" in Reseda, Calif., with their mother, who soon began to use drugs "pretty heavily" and left her kids to fend for themselves. "Griffin and I ran away three times, barefooted," she says. "We would steal sugary stuff out of the Jolly Jug (liquor store). I lived in a bathroom, saw maggots . . . real nice."

When O'Neal was 7, her father intervened and sent the children briefly to a boarding school in Arizona. Miserable and isolated, "I ended up cutting off my hair and sending it to my grandmother, begging her to take me home, " she recalls. When Moore checked into a Camarillo, Calif., mental hospital, Ryan -- who sometimes visited on weekends -- took Tatum to live with him in Malibu, while Griffin rejoined his mother. (O'Neal also has two younger half siblings: Patrick, Ryan's 34-year-old son with actress Leigh Taylor-Young, and Redmond, 17, his son with Fawcett.) Having recently starred in 1970's Love Story, Ryan "was this handsome playboy who wanted to take care of me," O'Neal recalls. The love-starved child soon became possessive of him -- following him everywhere and even climbing into his bed -- which ticked off his girlfriends, including former Bond girl Ursula Andress. "I don't want to sleep with you while your daughter is in the bed," O'Neal recalls Andress complaining. "It's weird."