I agree with Robyn too. I think there is more going with him than you do not know about. Perhaps it is better that you don't know right now and so he is not telling you.

Perhaps he is feeling trapped and claustrophobic and needs space. If he is complaining about your friends and roommates, that is a sure sign that there are much deeper seeded issues. You need to give him space or you will lose him.

Hun, this will sound harsh, but have you considered the idea that maybe he has outgrown the relationship and needs to move on to experience something new? I mean you guys sound so young. Too young to be so involved. Especially for a male. Males at your age, have no intrest in 'settling down'. They need space and if they start feeling smothered and start fights, it's a sure sign this is what is happening.