Pop star Demi Lovato is hesitant to resume her acting career after confessing she is still uncomfortable with on camera work after battling eating disorders for much of her youth.

The Skyscraper hitmaker, 21, spent time in rehab in 2010 and 2011 after suffering a breakdown on tour in South America, and she subsequently revealed she had been secretly struggling with self-harming, depression, drug addictions, anorexia and bulimia issues.

She managed to bounce back from the health woes with a new role as a judge on U.S. talent show The X Factor, but Lovato admits it takes a lot to overcome her nerves every time she steps out to appear onscreen.

As a result, Lovato confesses she is not ready to fully return to acting after wrapping up her hit children's show Sonny with a Chance in 2011 and filming a trio of guest appearances on hit show Glee.

She says, "It is still hard being in front of the camera when you have suffered from eating disorders, and I still don't watch my episodes. It is hard... I think ultimately my main thing is singing. Maybe movies once in a while, if the right role comes along."

Meanwhile, Lovato has opened up about the "deep and dark" period she endured during her personal battles and her surprise at the way she was received after leaving rehab.

She tells Entertainment Weekly magazine, "When I was in treatment, I honestly thought my career was over. But when I came out of treatment, I had more supportive fans than ever."

Lovato has detailed her journey through the ups and downs in her new book, Staying Strong: 365 Days a Year.