Demi Lovato is no stranger to publicity surrounding her personal battles, but she says she was nervous about actually opening up about them on camera for her upcoming MTV documentary. Demi Lovato checked into rehab in 2010 to address a number of issues, including an eating disorder, depression and self-harming. She is out now and has been doing a lot of promo appearances and performances, but she has also filmed a new MTV motivational documentary, entitled “Stay Strong,” to show support for fans suffering similar problems. She says quote: “I kind of talked about the journey that I've been on and I just want people to take away a positive message. It gets better, you know?" The show airs on MTV tomorrow night, and Demi will also take fan questions after the show, live in MTV’s Time Square studio.