22 and a loner

I'm 22 (male) and I've never had a girlfriend. I can't really think of an excuse as to why, other than my school life. They weren't all boy schools, but I was in a gifted program in middle school (Like 90% guys) and I was in a math/ science program (Now like 95% guys). By the time I went off to college (Engineering program: 99.9% guys) the desire had almost completely faded. I'm so comfortable NOT being in a relationship, it's just how I operate now.

To get a better picture of me, I'm a decent looking guy. I'm tall (6ft), I have an athletic build, strong jawline, I wear glasses, long dark wavy hair, I'm mixed race (Half trini, half white) so I have a light tan complexion.

I'm not bad at conversing, I can hold my own in a conversation, make people laugh. But I guess I'm really bad at approaching people. I almost never talk to people unless they say something to me first, or it's necessary to do so. So I'd never see a woman and think of going up and talking to her for no reason. If she's really beautiful I just tell myself "she's probably stuck-up" and look away. I know this is not normal, I know something needs to change. I thought I'd become more sociable when I stopped masturbating, but I'm still not able to find anyone I feel like pursuing.

Is there anything that you think I can do to find a girlfriend? Or even change my attitude? Please don't recommend dating sites, I think the people there are just looking for sex. I'm talking about finding someone I can feel at home with. Any advice would be appreciated.