Dewan describes her 2018 split from Tatum as a "loss of an idealistic future for myself and my life."
After an almost nine-year marriage, the two called it quits in April 2018. They share 6-year-old daughter Everly.
"I was just gutted. It was so difficult for me," Dewan told People. "It was the loss of an idealistic future for myself and my life. What does that now look like for me? Where do I begin? I met him when I was 24, I didn't know life without Chan."
She added, "I always say no one gets married to hopefully get divorced."
The 38-year-old dancer-turned-actress "never" expected her life "to take a turn," but she's grateful it did. She told the publication she leaned on family and friends but knew she had to put in the work herself -- and that involved coming to terms with the reality that some people grow together while others grow apart.
"People grow and they change and sometimes they don't grow and change together," she said. "So it wasn't [an] overnight thing that happened. There was no one event. I think it was just a slow realization that we wanted different things."
"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 continued. "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."
In the midst of adjusting to her family's "new normal," Dewan found new love with actor Steve Kazee, also 38. The two are expecting their first child together, and while she's thrilled about her pregnancy, she's also very focused on her No. 1 priority: Everly.
"We're all aware that it's a new normal, we're all getting used to it," Dewan said. "You can still have a relationship and just because the forms change as to who you are to each other, it doesn't take away from the love that [Channing and I] had or that we shared all those years."
"It wasn't easy necessarily, to get here, which nothing is easy in life, right?" she added. "I had to put in the work. This doesn't just happen overnight. But just to know that it's possible, and your perspective on life can change. It can change for the better, and you'll be fine."
They say timing is everything, and in Jenna and Steve's case, it was. Dewan was just starting to come "out of my grief tunnel" when Kazee popped back up in her life.
"I had met Steve years ago in a flash, it must've been five minutes," she recalled. "I saw him perform in 'Once' on Broadway and I was just totally blown away by his talent. My mom was with me, and we got to go backstage and meet the actors. He just had a cool [energy] about him."
"Obviously I was married and so we never spoke or saw each other again for six years, but I never forgot the moment," she went on. "And then six years later, obviously it becomes public knowledge that we're separated and he contacted me."
Dewan was adamant that she was "not at all looking for any kind of relationship. It was nothing I was looking for, but it was everything I needed, if that makes sense."
It started with a phone call that lasted for hours, and Dewan says there was an "immediate connection." The connection only got stronger in person.
"It was an instant connection when we met each other. All of a sudden," she told PEOPLE with a smile. "There was no way we could avoid it. So in my eyes it was truly, completely meant to be. There was like a lightning bolt behind it. I definitely was like, 'Okay, let me move through this slowly.' But it was too strong. It was too right,. And I said, 'What am I fighting?'"
Dewan "waited for a very, very, very long time" before introducing her daughter to her boyfriend, who eventually got Everly's full stamp of approval when he sent her a video of him playing guitar and singing a "My Little Pony" song.
Dewan's wellness book, "Gracefully You: How to Live Your Best Life Every Day," hits bookshelves Oct. 22.
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