In her new book, Gracefully You: Finding Beauty and Balance in the Everyday, the 38-year-old dancer writes about what she dubs "the separation storm," which "tested me in ways I hadn't thought possible."
"I was never challenged by anything more than I was by having to find grace during my divorce," she writes. "Not only was I fighting an emotional battle of having to let go and move forward in life, I was learning things about my ex most people wouldn't have to face -- and over the internet as it was happening."
"There I was, on a plane, alone, finding out about his new relationship," Dewan continues. "I felt blindsided. Choosing grace as I learned everything about my personal situation along with the rest of the world was really difficult."
Despite the "challenge to remain graceful," Dewan notes that it's in those uncomfortable situations "when your real character comes out."
"Instead of reacting the way I wanted to (there were many Twitter posts written, then deleted)... I asked myself this: How do I choose grace in this moment?" she recalls. "Had I not been practicing this way of life beforehand, I definitely wouldn't have handled this news very gracefully."
In addition to Tatum's new relationship, Dewan had to contend with the public nature of her breakup with Tatum, with whom she shares a 6-year-old daughter, Everly.
"In the beginning of my separation, it felt as though I were in a dark closet, desperately trying to find the light or the way out. I was in a state of shock," she writes. "One week I'd be doing really well and the next I was slammed with a whole new slew of emotions."
"The rumor mill was churning out story after story. There were many times I hid under the covers, wondering what was next," Dewan continues. "The pain hit me like a tumbling avalanche. I was completely overcome with fear and sadness. It took many moments of sitting alone with my grief to force me into surrendering to my roller coaster of a situation."
"When I was ready, I started dating someone amazing," she writes. "It was this cosmically great thing where we circled back around toward each other after a moment of instant recognition years ago."
Gracefully You: Finding Beauty and Balance in the Everyday will hit shelves Oct. 22.