What do I do? How do I get him back?

By the way, I will offer you the same assistance as I offered this lady here: link

Just let me know the guy's first name either here or in a pm.

You're asking the wrong guy. Ask God! Don't you understand yet Who's running this show? Pray, and I will pray too. Then let's touch base again next week and see if your problem was solved.

I think you need to take some time to yourself first right now your relationship with him isn't healthy. So take a break then you may be able to talk to him about starting over, but you need to not be so obsessive image if the rolls were reversed and you were him and his girlfriend is calling him 20+ times going to your house and school it would be a bit scary. He needs space jsut like everyone in the world so collect yourself if you guys work it out and if he doesn't answer your call don't freak take a breath and go about your day.

I don't mean to sound harsh by saying this, but you really need to back off. You admit your acting psycho, but you're more concerned with getting him back than you are fixing your problem. The truth is, you can't be with anyone right now until you work on yourself. Take it from someone who has been there.you can't act like that and expect someone to look past it. It won't happen. I don't know if this is just immaturity or if there is something from your past causing you to act this way.but you HAVE to calm down. You should try to buy some books about jealousy and anger.they help.
If you truly want to make things work with this guy, then you need t prove that you are trying to change.otherwise, I don't see how it can work. I wish you luck!