Demi Lovato has been looking fabulous on The X Factor but the starlet hasn’t always been comfortable in her own skin.

After seeking treatment two year ago for many issues, including an eating disorder, the 20-year-old is diving deeper into her past, "I remember being 3 years old in a diaper and rubbing my hand over my stomach," Lovato recalls on Monday’s Katie. "I remember thinking in my head, 'I wonder if one day this will ever be flat?'"

During her appearance with Katie Couric the actress/singer opened up about bullying as well, "It played more of a toll on me than if I was physically abused in school.  I've always said I wished that they had just hit me in the face and gotten it over with, because what they said to me sticks to me to this day."

Despite her hardships growing up, Demi has chosen to use her experience to help others and announced Thursday that she is the new ambassador for Secret deodrant’s “Mean Stinks” anti-bullying campaign.