Shania Twain has had some big ups in her career -- her 1997 release, 'Come On Over,' was the best-selling album of all time by a female artist in any genre -- but in her upcoming autobiography, the Canadian singer tells the story of her less-than-perfect personal life.

"There have been moments in my life I was concerned by the reality that tomorrow would never come," Twain says of the book. The 'Any Man of Mine' star has faced lots of turmoil in her life,  from losing both parents in a fatal car crash in the late '80s, to her rocky divorce from Robert "Mutt" Lange just last year. Twain adds, "Recently I experienced one of those moments to an intensity that brought on a sudden urgency to document my life before I ran out of time."

Though Twain is only 45, she's been through enough in her lifetime to appreciate the value of time. "I began writing this book with a sincere respect for the past, present and future as something never to be taken for granted," she says of the currently unnamed autobiography, which she refers to as "an honest and complete account of my life, in my own words."

Twain's autobiography is set for release on May 3. In addition to the tell-all book, Twain will also debut a docu-series on Oprah's OWN Network this spring.

Watch the Shania Twain 'From This Moment On' Video