Demi Moore Discovered Ashton Kutcher's Affair Via Google Alert: "I Could Barely Take a Breath"

While promoting her new memoir, 'Inside Out,' Moore opened up to Diane Sawyer about her "devastating" split from the actor.

To promote her new memoir, Inside Out, Demi Moore sat down with Diane Sawyer in an interview that will roll out in multiple parts this week on ABC's Good Morning America. During Tuesday's second installment, Moore, 56, opened up about her split from ex-husband Ashton Kutcher, 41, which she described as "devastating."

Among other revelations, the actress shared that she discovered Kutcher was "caught cheating" from a Google Alert on her cellphone. San Diego-based administrative assistant Sara Leal shared intimate details of her interactions with Kutcher, which took place in 2011 during the actor's marriage to Moore, in an interview with Us Weekly. (Kutcher and Moore wed in 2005 and finalized their divorce in 2013.)

Moore told Sawyer that she immediately called Kutcher and "asked if it was true." Moore went on to say that Kutcher "admitted it right away." She recounted, "And I think my response was, 'Are you fucking kidding me?' That was it. And I think I could barely take a breath."

Not long after the call, Moore had to walk a red carpet for a miniseries that she directed for Lifetime, smiling through the pain. "I have this incredible, incredible self-protection," she said. "I often like to refer to it as my own personal Iron Man suit. I can literally put it on and it's just like — I can disassociate."

Moore also discussed another sad moment in her marriage to Kutcher: suffering a miscarriage. At 42, Moore became pregnant but lost the baby at nearly six months. "You could see a combination of his dread," she remembered of watching her doctor's face. "And it shifting then immediately into matter-of-fact, practical information — because it was unquestionable, because there was no heartbeat."

Moore tried to get pregnant again with the help of in vitro fertilization "quite a few times," but was ultimately unsuccessful. Then, after 20 years of sobriety, she turned to alcohol again and started taking prescription pills like Vicodin. Moore described that part of her life as "lost, empty, desperate, confused." She added, "I really lost sight of everything that was in front of me, which is the family I had."

Moore shares daughters Rumer, 31; Scout, 28; and Tallulah, 25, with ex-husband Bruce Willis, whom she divorced in 2000 after nearly 13 years of marriage.

"I was a 40-year-old who had a big life," Moore writes in her book, detailing the beginning stages of her romance with Kutcher, who was 25 when the pair first met. "And Ashton's adult life was just beginning — I didn't see all that because I was inside of it. I just felt like a 15-year-old girl hoping somebody liked me."

Moore — who moved to Hollywood as a teen to pursue acting after attempting to escape a turbulent childhood in New Mexico — told Sawyer that she thought she had been "responsible for so much of my life, and all of a sudden this window opened up where I was safe."

"[Kutcher] loved my children — it wasn't something he feared. He seemed to be comfortable with the enormity of the ex-husband," Moore recalled. "I mean, you know, I felt like I was not coming with baggage, I had trunks."

In the portion of the interview that aired Wednesday on GMA, Moore opened up about the 2012 seizure she had at a birthday party after using drugs, inhaling synthetic pot and nitrous oxide. "Everyone else [at the party] was witnessing my body failing," she said. "My daughter [was] terrified that she was gonna see me die right in front of her. And within me, I was in a place that was thinking, 'Wow, how did I get in here? Isn't this interesting?'"

Continued Moore, "And then my very next thought was, 'Oh, I wonder if I can get out?' And all of a sudden, I was back in my body. I think it was a moment that I was somehow being given a choice."

Moore said that the scare was a turning point for her. "I think something had to give," she explained to Sawyer. "When you come up to those places, you either go in or you go out."

Watch Moore's interview with Sawyer below.

Sept. 25, 7:03 a.m. This story has been updated with more of Moore's interview, which aired Wednesday on GMA.