In her forthcoming wellness book, Gracefully You: How to Live Your Best Life Every Day, Dewan, 38, said that she “felt blindsided” when news of Tatum’s relationship with singer Jessie J was first revealed in October 2018.
“I was learning things about my ex most people wouldn’t have to face–and over the internet, as it was happening,” she wrote in an excerpt published by E!.
“There I was, on a plane, alone, finding out about his new relationship. I felt blindsided. Choosing grace as I learned everything about my personal situation along with the rest of the world was really difficult,” she added.
Channing and Dewan, who share 6-year-old daughter Everly, announced their separation in April 2018 after nine years of marriage and filed for divorce on Oct. 26, citing irreconcilable differences.
As her ex moved on, Dewan also found love again with Tony Award-winning actor Steve Kazee, with whom she’s expecting her second child.
“When I was ready, I started dating someone amazing,” she wrote, according to E!. “It was this cosmically great thing where we circled back around each other after a moment of instant recognition years ago.”
While Dewan may have been surprised by the fact that her ex had moved on, she has spoken out in support of Jessie J in the past.
After the British singer, 31, slammed commenters who were continually comparing her appearance to Dewan’s, the actress and dancer praised Jessie J for encouraging others to lift up women, instead of “picking favorites.”
“Amen Jessie! Yes!!!! Women for women all the way. No need for negativity. Let’s live in a world where we support each other and raise each other up. Like I said before, positive vibes all the way. Nothing but respect,” Dewan shared in an online post.
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Opening up about how much her life changed in the wake of her split from Tatum, Dewan recently told PEOPLE “it was a hard journey of growth and change.”
“People grow and they change and sometimes they don’t grow and change together. So it wasn’t a overnight thing that happened,” she said. “There was no one event. I think it was just a slow realization that we wanted different things.”
After leaning on her loved ones for support, Dewan realized that ultimately she had to put in the work herself.
“You would never expect your life to take a turn the way it does,” she said. “But embracing it and starting fresh and figuring out what you want in life and what means a lot to you and what’s meaningful, what is going to make you happy,” she said. “I’m grateful that I now am at a place where I understand myself and what I want and I’m happy about this new chapter. I’m in a place of joy.”
Dewan’s book, Gracefully You: How to Live Your Best Life Every Day, hits bookshelves on Oct. 22.