I treated my girlfriend like dirt, and now i'm scared of losing her?

You HAVE to explain to her why you got so angry. Tell her that you got really jealous and that because you love her it was like a protective instinct to not want them to touch her there. Tell her that you love her to death (taken from how you explained you do above) and apologize. Tell her it won't happen again but you will tell her from now on when you feel the way you did toward the guys.