If you and your friend haven't already done so, start taking shooting classes and get your CCL's. Obviously used ONLY in defense and to protect life, and not to show or intimidate the crowd you're referring to. PRACTICE, PRACTICE, PRACTICE.
MOVE OUT of that neighborhood. Get another job if you have to. Get a room mate, move back with your parents, - whatever it takes, get out of there. Not worth living in FEAR. You don't want to be in that environment, much less when the SHTF. Change your situation.
I went exactly what you went through in NYC and my ONLY goal at the time was to get the Fuck OUT. There are "people" that are comfortable in that environment. Most of them are called "predators" and you and your friend sound like "prey". You do what you have to to adapt, and SURVIVE. BUT I can't stress it enough - GET OUT!
BTW - HUG
http://www.mediafire.com/?s4snpbpsts5b3 - Thx sovereignjanice