How to forget the past, forgive myself and others? How to trust again.?

I am a 20 year old, male. When I was about 9 and then again when in the Army, was d. The most recent time, I was drugged. Because of these incidents I have developed an extreme ual insecurity for some reason. I constantly question my girlfriend about her faithfulness. She lives across the world and makes my constant paranoia unbearable. I quiz her about her past and ask about details about her ex(s) ual performance and "size". I would at times even fantasize about her and her ex's. At one time, in order to spite her for hanging out with an ex, I cheated on her by kissing and performing other ual activities with a stranger. However, when it came time to actually "do it" I lost my and was filled with guilt. So now, I look for reasons to end my relationship. I become insanely jealous when she goes with her friends to clubs and parties. I even believe myself when I blow things out of proportion and blame her. I know, I'm a freak. I feel like love is a curse and I'm condemned to a life of loneliness. Unless I change. Neither of us are angels (there is more to the story). So finally, the question... How do I get past the ual insecurities, stop being so jealous, trust her and forgive myself? Thank you for any advice.