Demi Lovato has had an interesting year, to say the least. After leaving treatment in January 2011, she focused on her work, going into the studio to make the fun — but still very personal — album Unbroken. She launched a tour that quickly became viral thanks to her emotional cover of Lil Wayne's "How to Love." She put the pieces back together, while remaining completely honest with her fans about her issues. Lovato gets personal and tells her story in the MTV documentary "Demi Lovato: Stay Strong," airing Tuesday.

"I've just been working at it a day at a time and have been trying to continue to fight my hardest," she told MTV News about still dealing with her problems. "And I've had my ups and downs, and I'm still trying, but overall it's been a really great journey, and I'm thankful for everything that I've been through."

Her single "Skyscraper" topped the charts, and her fans turned it out when she toured last fall, but there's one moment that really is the tops for Lovato: "I won Favorite Pop Artist at the People's Choice Awards," she said of the January awards ceremony where she performed her new single, "Give Your Heart a Break." "So that was the highlight of my year so far. I worked really hard towards that, and it was just amazing."

Now, though, as Lovato looks to the future, she says that anyone can rewrite their story and shift the focus to the positive. It's a message she hopes her fans can take with them. "I think it's important to make sure that people know there's a positive side to it, that you can kind of rework your story no matter what," she said. "I'm just trying to be an example for girls today."

"Demi Lovato: Stay Strong" airs at 10 p.m. ET/PT Tuesday on MTV.