Next time you get jumped, just buy a gun. And a silencer, if possible, so then you can kill future-jumpees without drawing too much attention to yourself.
When killing others, attention = bad.
And if you're really not a shooty-kinda guy, you could get some other weapon. Brass knuckles, for instance.
Don't just "get over" your fears, let them boil into an almost-uncontrollable rage (You have to keep
some control) which you can freely unleash on anyone who screws with you.
