Demi Lovato's problems extend much further than her 2010 split with Joe Jonas. Though the 18-year-old singer was forced to see her ex daily during the "Camp Rock 2" tour, Lovato tells 's September issue that the pain of their breakup had little to do with her decision to seek treatment last November.
"I wouldn't credit my meltdown to a guy," Lovato says. "There was so much other stuff in my life."
Bullied for her weight as a kid, Lovato began overeating when she was 8 years old. "Those girls never gave me an explanation for why they were bullying me. One of the words they called me was 'fat.' At that age, you think, 'Oh, so I don't have friends because I'm fat.'"
Lovato's depression worsened three years later when she began cutting herself. When the "Skyscraper" singer showed up to an event in 2008 with suspicious red marks on her wrists, Lovato's handlers devised a plan to cover up what was really going on.
"I don't think I would have been ready to talk about [my problems] then, but I could've come up with something better than gummy bracelets," Lovato says. "Needless to say, that publicist is no longer with us...I mean, she's alive."
Though Lovato tried to keep her personal problems a secret over the next few years, things reached a boiling point in 2010 when she hit back-up dancer Alex Welch on a flight out of Bogota, Colombia.
"I was completely out of line all summer. Just the worst attitude -- totally ungrateful," Lovato tells . "I just felt like [Welch] had betrayed me. When you punch someone on a plane, enough is enough."