I feel im really uninteresting.... help..?

I cant seem to express myself at all around people, even my family. Ive been picked on all my life to where everyday of school was a living hell. Death threats and attempts occurred in my early life for no apparent reason. No one listened to me and never trusted me. I never trusted anyone and still have a hard time trying to trust people. People always put me down for any reason at all... I want to open up but I constantly get flashbacks of the past. Whenever i go out somewhere i always get nervous to where i feel angry for no reason. What can i do to release this prolonged anger??