On another viewpoint, this looks like a very claustrophobic relationship. I know you want him "all to yourself" all the time, but remember that University is a big experience for everyone, and everyone wants their own experience.
He wants his friends, and sure, you want yours too. That doesn't mean you can't have mutual friends - but let him have some air. Just because he's going with friends somewhere doesn't mean he doesn't love you or want to spend time with you, its because he wants to spend some time with some other people.
If you don't spend time with other friends aswell as each other, you won't have many close friends left, and your relationship will suffer because of spending too much time together.
As for him saying its over, that is hurtful and he may appreciate that. He sounds so frustrated that you won't let him even go out with other friends for just one night. Your relationship is still quite immature and early, and you both need to learn TRUST. Remember that this relationship stuff is two-way - how would you feel if it was the other way around and he stopped you going out all the time?
I'm sure everythings ok and he does love you still, but give the guy abit of room, and don't be disheartened if he doesn't text back immediately or wants to go out. You are still at the same uni and can see each other often.