By Sharon Cotliar
May 02, 2011 12:00 PM

When Disney Channel star Demi Lovato pulled up to the Timberline Knolls treatment center near Chicago on Oct. 30, she didn’t know what to expect. After saying goodbye to her mom and stepdad, Dianna and Eddie De La Garza, “I went in and I immediately saw 15 girls,” says Lovato. “They said hi to me, and I saw some of them were whispering, which instantly made me feel uncomfortable. But a week later everyone was like, ‘We don’t care who you are. We think it’s so brave that you came here.'”

Now Lovato, 18, is taking her courage to a whole new level: In an in-depth interview following her intense, three-month course of in-patient treatment at the center-which specializes in helping women with eating and mood disorders-the singer-actress is candidly speaking out about her longtime struggle with anorexia and bulimia. “My eating disorders have ruined my life,” she says as she curls up on the couch in the guesthouse she lives in, which sits behind the L.A.-area home her parents share with her sisters Dallas Lovato, 23, and Desperate Housewives star Madison De La Garza, 9. (Lovato is estranged from her biological father.) “I thought I could control it, but I couldn’t,” says Lovato, who also sought help for cutting, a form of self-harm. “I ended up in treatment at the most untimely moment in my life.”

In fact Lovato was on the same fast track to fame as fellow Disney darlings Miley Cyrus and Selena Gomez: Last fall Lovato was headlining her own Disney Channel series, Sonny with a Chance, and embarking on the South American leg of a world tour with the Jonas Brothers (at the time, she and Joe Jonas had recently broken up). But her seemingly charmed life shattered when she made headlines for seeking treatment after punching her backup dancer Alex Welch following a concert in Colombia last October. “The tabloids are always looking for the next train wreck, and I knew they’d pin me as one of them,” says Lovato. “In reality, I’m a teenage girl with real issues, and I needed to address them.”

Since completing her stay at Timberline Knolls on Jan. 27, Lovato has been slowly rebuilding her life in L.A., where she continues to work with a therapist, a nutritionist and a sponsor. “Demi has come so far,” says her stepdad, Eddie. “The journey has been a very difficult one.” No matter how tough it gets, “I’m determined to fight this,” says Lovato, who also hopes that by opening up about her “darkest time” she can reach those battling similar demons. “I’ve never been more peaceful or happy in my life. What’s important is to help others get to this place.”

What do you remember about the night you punched Alex Welch?

I was manic. I was hurt. I just exploded. Everything built up to this point, and I took it out on someone who was my friend. It’s normal for someone to have a breakdown, but what’s not normal is to hit someone. I felt horrible.

Did you go to treatment willingly?

Yes and no. I flew back to the U.S. and I thought we were going to L.A. My parents were like, “No, you’re going to Dallas. We have the owner of a treatment center waiting to talk to you and, if you’d like, take you to Chicago.” I knew that even if I didn’t want to go, that I had to do it for myself.

Looking back, when did you first worry about your weight?

At 12 years old, I was bullied in school. Girls were calling me fat, so I thought, “That’s the reason I don’t have any friends.” So I stopped eating. I became very weight-conscious, and I lost 30 lbs. I went down to 95 lbs.

Did you ever try to get help?

Yeah, we put a Band-Aid on it. I worked with a life coach. I thought it was enough, so everyone else thought it was enough. In reality, I was still only eating a meal a day…. When I was about 15, I was only eating two meals a week, but I wasn’t losing any more weight because my body adjusted to that. So I tried new things: laxatives, fasts-nothing was working. I decided maybe I should start throwing up. At my worst, I was doing it five times a day. I threw up so hard and so much, it was just blood in the toilet.

Your bulimia started at 15, which is when you filmed Camp Rock. Did you feel pressure to fit into a certain image at that time?

With Disney Channel, no one said, “Lose weight.” They never put pressure on me. The spotlight didn’t cause this. It just contributed a little bit. I looked at blogs; I saw nasty comments.

How did you hide that you weren’t eating?

I kept myself really busy. On lunch breaks on Sonny with a Chance, instead of eating, I would take naps or I’d say, “I gotta get my nails done!” I’d also go out with my friends more than normal. That’s something I tell my parents to watch for today: If I’m not really around the house, ask me how I’m doing, because most likely there’s something going on.

You were also secretly cutting yourself. When photos showed scars on your wrist in ’08, your reps said they were caused by rubber bracelets. Why didn’t you come clean then?

I wasn’t ready, because self-harming is such a taboo to talk about…. I saw it on TV, and I wondered what it would feel like. It was purely out of curiosity. Later, for me, it was a way of relieving pressure when I was stressed and had anxiety. When someone sees it, it’s terrifying, so I started doing it in areas where no one can see.

Were you abusing drugs or alcohol?

I’d be lying if I said I never touched anything. Fortunately it never got to a place where I had to be in treatment for it.

Did you struggle with other issues?

I’ve battled depression from a young age. I never found out until I went into treatment that I am bipolar [a disorder that causes dramatic and sometimes violent mood swings]. At first I was like, “What does that even mean?” But looking back, it makes sense. There were times when I was so manic I was writing seven songs in one night … that’s why I wasn’t happy when everything in my life was great. I’m being treated for it with medication and therapy.

What was treatment like for you?

I worked harder in those three months than I ever did in my life. I basically went through hours of therapy every day. I couldn’t use the bathroom by myself until I got those privileges. We weren’t allowed to have razors. I didn’t have Internet. We had certain phone times that were very strict. It was a battle, but I stuck it out.

Did your friends reach out to you?

Selena [Gomez] and I reconnected the first week. We hadn’t spoken in a long time. I take the blame; I feel like it was because of the way I had been acting. She called me, and she was the one crying. I’m like, “Selena, I’m the one in treatment. I’m the one who should be crying!” By the end of the conversation, we were both laughing. She’s continued to be there as a support.

What is eating like for you now?

It is more difficult now because I don’t have people supervising me. That’s why I haven’t been working: My goal for every day is to eat three meals, and that’s challenging enough. There are days where I feel so overwhelmed, like I can’t do it. My dad eats breakfast with me almost every day. I normally eat dinner with friends. But lunch is usually on my own, and I find that more difficult. I’m still learning just to like food.

Why aren’t you returning to Sonny with a Chance?

It made sense for me to leave the show to focus on my music. In the studio you don’t see my body, and I feel all of my confidence is in my voice. I don’t know if I could handle being in front of a camera with my body right now.

How have you stayed so strong during your recovery?

I take it day by day. I’d be lying if I said there weren’t days where I just want to stay in bed all day because I’m ashamed of my body. It’s a struggle I’ll probably have to deal with for the rest of my life. But I have so much life to live; I don’t want to waste it. It’s a new chapter in my life, starting now.