You should watch Wanted
http://www.imdb.com/title/tt0493464/ . haha actually that helped me out. I guess I just watched it at the right time in my life. But really, what I'm saying is figure out something that you are good at or something that makes you happy. Make a list of the good, no the GREAT things about yourself. Read it before you go to bed and when you wake up.
Do you meditate or do anything relaxing? Clear your mind and think about great things about yourself. Try to do this a couple times a day.
Surround yourself with good people.
Take back your life!! There are so many people out there that will try to bring you down - intentionally or not. Stand above that. Step out of the picture for a second and look at your situation. You are strong and confident inside. Yes it is easy to lose track of that, but try to put yourself above all negative things. Keep your head up!