Why did he have to stay there? (Did he not have money for a cab or could not call you)
Did you tell him that him going out with this guy was a bit upsetting?
Were you there to spend time with him when he went out or were you busy?
Do you live together?
We do not live together.
I have hinted to him that I don't really like him. Reason being is that when I was introduced to his friend for the first time, (mind you when my boyfriend wasn't around) his first two statements were "so, do you really love him," and when I said yes he said "oh nevermind then." I told my boyfriend about what he said "oh that's just Jimmy" and shrugged it off.
When he went out, we weren't hanging out. I told him I had an hour if he wanted to hang out for that, but he said what's the point because it was only an hour.
It sounds like he is frustrated about the amount of time you are spending together, which is a typical guy thing. Men often become more like boys when they feel they are not getting enough attention. Though the fact remains that your schooling is far more important right now then his attention needs. While I wish I could tell you that he will eventually get over it the reality is without some communication this is going to get a lot worse.
Him telling you, it wasn't worth it for only a hour shows that he is frustrated and trying to get you to see this is getting to a boiling point for him. Which in this case is pretty immature and not something you would want to see in a man you want a future with.
What I would suggest is a good sit down. Try to find some time where you can sit down and talk to him and let him know that while you love him his behavior is not helpful in this situation. Let him know that while you wish you could spend more time with him the reality is school is very important as this is your future you are working on. Let him know that you want to be with him when you can, but him taking off with his friends all the time and acting out towards you is hurting your feelings and with all the pressure at school it is something you are hoping you can both work on.
In reality this is his problem, not yours. The fact is your schooling is far more important then anything else right now. If he can not accept that then you may want to consider moving on. The fact is you need someone who is going to support you and understand that your schooling must come first. If he can not accept that then he may be to immature for a real relationship right now.