From PEOPLE Magazine Click to enlarge
Shania Twain has performed in front of stadiums full of fans, sold 76 million albums, won five Grammys, raised a son, written a memoir.... There's not much left to check off her list. And, she points out, "when you're in a moment of being satisfied and happy and content, your bucket list is pretty short. So I don't really have a list right now."

Happy and content. That's a far cry from three years ago, when she found out that her 14-year marriage was over-and that her husband and producer, Robert "Mutt" Lange, was allegedly having an affair with her best friend. What helped Twain, 45, get her groove back was equally surprising: She found love with the other woman's ex-husband, Frédéric Thiébaud. "I didn't want to love again-it was the last thing on my mind," she says, sitting in the living room of the home in the Bahamas she shares with Thiébaud, whom she wed on Jan. 1. "It's just amazing how life works."

The shocking double betrayal left her "ready to die," as she writes in her new memoir From This Moment On. It was Thiébaud who broke the news to her. "He had the classic evidence in the form of phone bills, hotel information and receipts, and the memory of a garter belt and lingerie he saw packed in her luggage [when] she was meant to be going away for time 'alone,'" she writes.

At first Twain was in denial-and neither her ex-husband nor her former friend Marie-Anne ever gave her any explanation. (The pair-who, as far as Twain knows, are still together-have denied the allegations of an affair.) The one time the two women crossed paths, "all I could say was 'You're a bad person,'" Twain recalls. "It just wasn't enough." She resorted to sending Marie-Anne e-mails-first angry, then pleading. One read, "If you could see me crying and suffering, maybe you would have pity. Find love somewhere else from someone else that isn't hurting two families so much." She says, "I'll never be okay with how my marriage ended. But you have to accept that's what was meant to be."

Twain still struggles with another repercussion of the breakup: She lost the ability to sing. Diagnosed last year with dysphonia (a condition in which the muscles around the voice box constrict it), she attributes the problem to the stress she's had in her life, capped off by her divorce. Her new docuseries on the Oprah Winfrey Network, Why Not? with Shania Twain, follows her attempt to find her voice again as she considers a headlining gig at Caesars Palace in Las Vegas. Twain, who in June will appear at the CMA Music Festival for the first time since 1996, is also working on new music. "More than ever," she says, "I'm putting my feelings into the songs I'm writing."

Surely there will be love songs. Twain and Thiébaud bonded over their shared pain-and the friendship developed into more. "I rejected it initially," says Twain. "But I couldn't control Fred's love for me and how easy he is to love." With her son Eja, 9, and his daughter Johanna, 10, they divide their time between Switzerland and the Bahamas. Says Thiébaud, 40: "I'm more in love with her every day."

Relishing her second chance at love, Twain is a woman transformed. "My closest friends and family say they haven't seen me this free-spirited and happy in years," she says. "And it's true. It's definitely true."