If you're not into socializing, then forcing yourself to do it just to get a girlfriend is not going to work.

Your best option is to identify your centers of interest, and turn them into activities that you can share with other people, girls included.

You do seem to hang out with some friends, so there's a form of socialization you find acceptable (why does that one work and not the other?). If they have girlfriends, their girlfriends probably also have other girl friends. Get introduced to them, perhaps in the occasions that you do socialize with your friends.