Shania Twain continues to make the TV rounds, talking about her new autobiography, 'From This Moment On,' which chronicles the highs and lows of both her career and personal life -- including her much publicized divorce from first husband Robert 'Mutt' Lange after his alleged affair.

The betrayal, she explains, was that much more bitter because the object of his affection was her close friend and secretary, Marie-Anne Thiébaud, who was also married at the time. The news of the alleged infidelity came from none other than Marie-Anne's own then-husband, Frédéric Thiébaud.

"It was Easter time, and we were two families spending the holidays together, is what I thought," she reveals in an intimate chat on the 'Ellen DeGeneres Show.' "Fred and I did not have a one-on-one relationship at all. It was quite a formal relationship, really. He didn't have my personal phone number, for example, but he found out how to reach me. He said, 'I need to talk to you about Mutt and Marie-Anne. Can I come and see you?' He just basically explained that, 'I'd been waiting for a few weeks to tell you, I'd been hoping that they would tell you themselves, and I think you need to know,' and then he told me."

The Canadian superstar acknowledges she didn't take the news very well.

"Of course, I didn't believe him and I thought for sure he was making it up," she admits. "I was obviously just in denial on my part. He just said, 'I have proof if you want it. I've been following it now for a few weeks, and I've got hotel bills and all kinds of details.' I don't go into the details in the book, so if that's what you're looking for, you probably don't want to read it. I don't go into the details about the affair because it's not necessary. I talk more about how it affected me and what I learned from it."

Shania still didn't want to believe that her closest confidant and the father of her son, 10-year-old Eja, would commit such an act of betrayal together.

"I called [Marie-Anne] up and said, 'Why don't you come over? I want to talk to you about something,'" recalls the singer. "I asked her if there was anything she needed to tell me. I wanted to give her the opportunity to tell me herself without me accusing her. Because at this point, I wasn't sure that Fred might have been exaggerating or something. She said, 'No, I really don't know what to tell you. I don't understand why you think I would ever hide anything from you.'"

The multi-platinum-selling singer writes about those devastating moments in her book:

"For the first week after finding out about the affair, I was ready to die. To go to bed forever and never wake up. Or to hurt someone. I was ready to do something desperate. But in reality, there was nothing to do but to suffer through it. Fortunately when you're a mom, the responsibility of caring for your child can keep you going."

Ironically, Shania ultimately found solace in the one person who could fully understand the depth of her suffering: Marie-Anne's former husband.

"It unraveled very slowly from there. It took a long time to deal with, and it's a very slow grieving process on my end, and on Fred's end obviously," explains the country icon. "We slowly became very, very good friends. We had many months of just trying to make sense of everything, holding each other up. It was a very difficult time emotionally for both of us. I would say he was probably stronger than I was. He was a tremendous support -- we were a support to each other -- and really found something beautiful in the end and unexpected."

The unexpected ending, of course, was her new love with Fred, who became her husband earlier this year.

"This is why it's easy for me to talk about in the sense that I'm not angry when I talk about it anymore," she notes. "I'm not even really confused because it's obvious life just has to play out the way it's meant to, and how can I complain with the way it ended up? Of course it was painful. It's more difficult, to be honest, to talk about other elements of my life with the public, because the divorce and the betrayal was already splattered all over the tabloids without me having anything to do with it, and I've already gone through that humiliation and embarrassment. For me, I've already gone through that part, in the public, and now it's easier to talk about than a lot of other things."

While she is thrilled with how the new chapter of her life is unfolding, she adds she chooses to stay clear of anything that has to do with Mutt's relationship with Marie-Anne. Acknowledging she has no idea if the former flames are still together, she says, "It doesn't matter anymore. It's no longer my business."

The new memoir was one of the biggest tools in helping Shania recover from the betrayal and learn to trust again.

"Part of writing the whole book and starting from the beginning of my life was to put that back part of my life into more perspective," the resilient 45-year-old notes. "It doesn't define who I am and it doesn't define my whole life. My whole life is a much bigger picture, and writing the book from the beginning gave perspective to that one very difficult time. Really, it's just a part of my life."

Shania is ready to return to the public eye again. She recently debuted a new series on Oprah Winfrey's OWN Network, 'Why Not?,' which scored the highest-rated premiere of any show on the new network. She is also making a long-awaited return to Nashville's CMA Music Festival, where she will also be on hand to greet fans and sign autographs.

You Think You Know Shania Twain?

Do You Know Shania Twain's Real Name?

More From TheBoot