Why can't you hang out with your friends, but not go to the parties? You can still socialize during the school day and catch lunch/dinner with people.

I have plenty of friends who are your age or older who have never had a boyfriend. I think I told you this before, but you're not alone.

With girls, you should try to become friends with them and see where it goes from there. Have lunch with them and keep it casual. If you can get past lunch, you can have dinner with them and go on from there.

Have you thought about joining on campus clubs? Clubs are a good way to meet people who have similar goals/interests to you.