How can I stop acting tough?

I know this might seem like a funny question but truth is I really don't know how to. I feel like I've transformed into this bad guy and now this is all I know. You see my dad got locked up while I was oboe 2 years old and I use to get picked on as a kid. I use get bullied and kicked around not only by a couple of kids but by the whole entire school. The girls use to make me feel like sh*t and every kid use to treat me like a punching bag. Because of that I have always felt like the the only way I wouldn't let anyone see me as a easy target was to act tough and get into fights. In middle school my name started spreading around and I started dating girls but I also started hanging out without the wrong crew. During that time I got jumped into a gang but it didn't ruin my life thanks to my mom because she made me move and I was able to leave it as soon as I joined. Now that I'm in high school I feel like the old me is trying to reach out to me. I feel like everywhere I go people are going to see me as this person I portrayed. I don't even trust myself around anyone because I always feel like they're going think I'm a bad person even though they don't know me and this has really ruined my social life. I don't wan't to hang out with the wrong crew and people just see me as this person so I really I have no one to turn to so I really got no friends. I try the best I can to change but it really doesn't help that I live in the bad parts of NY and for some reason I can't take this look off my face that always makes me look mad (I guess it because I've lived a sh*tty life).... I just want to settle down with a nice girl, go to college and live a normal life!....