Pop star Demi Lovato has been honest about her struggles.

Lovato, who has been famous since childhood when she was cast in "Barney and Friends," has suffered through addiction, depression, eating disorders and bullying. She writes about her struggles in a book that hits stores Tuesday.

In " Staying Strong: 365 Days a Year," the 21-year-old "Give Your Heart a Break" singer shares her most honest and hopeful insights. It's a diary, of sorts, which also includes inspirational sayings from Albert Einstein and Aristotle to Tupac Shakur and Nicki Minaj.

In an interview with "GMA"'s Lara Spencer, Lovato, a judge on "The X-Factor," explained the motivation behind the book.

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She said fans have often told her that her experiences have helped them to get into recovery, but many others ask how she continues to stay strong.

"And over the past few years I've done this thing, a morning meditation, basically, where I read out of a book and it's a quote, a passage, and a goal for the day, so basically what I wanted to do was do that for my fans," she said.

In the book she's vocal about the topic of bullying. Even though she has been bullied, she comes to the defense of bullies and says people should hug a bully.

When Spencer asked her why, Lovato replied, "There was a time where I really resented the people that bullied me in my life, and I lived with so much hate that I only ended up making myself sick."

She reached out to one of the girls that had tormented her and gained a new perspective.

"I was able to talk to her and really kind of clear up any hatred or animosity … and I realized that she was going through things at that time that I had no idea about," she said.

In the book, she also says that time and love can heal everything.

She told Spencer that a trip to Kenya for her 21 st birthday changed her life and cemented her recovery.

Her time in that country - and being able to meet and help the people there - was "better than any other drug I've ever done," she said.