Jenna Dewan has told how she felt "blindsided" by Channing Tatum's relationship with Jessie J.

The 38-year-old candidly opened up about her split from the Magic Mike actor in her new book,  Gracefully You: Finding Beauty and Balance in the Everyday.  She explained [via E! News] that divorce was "never on my docket of dreams", as she explained how she had worked through her feelings. She continued:

"In the beginning I turned to the typical remedies. I drank a whole lot of wine with friends. I had many moments of deep, painful, big cries. And both were very necessary in getting me to the next hour, through the day, on to another week. "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. 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."

She recalled how the pain of their separation hit her "like a tumbling avalanche," leaving her feeling "completely overcome with fear and sadness." Dewan added:

"It took many moments of sitting alone with my grief to force me into surrendering to my roller coaster of a situation."

The actress, who shares six-year-old daughter Everly with Tatum, also spoke about how she felt "blindsided" when she found out about her ex husband's new relationship. She continued:

"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. I felt blindsided. Choosing grace as I learned everything about my personal situation along with the rest of the world was really difficult."

• Gracefully You: Finding Beauty and Balance in the Everyday will be available on October 31.