I think there is more going with him than you do not know about. Greenpunkergirl is right....he's looking around to see what else is out there for the picking.

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.

You guys are just becoming in life...this is probably what he is thinking...just becoming...'Why am I wasting my time here when I could be out partying and doing what my buddies are all doing". This is normal behaviour for guys his age. He will do anything to get out of seeing you so he can party with his guy friends...if starting a fight does it....he will.

I am sorry this is happening to you. It is a really tough thing to go through. All of us at some time or another have been through a breakup and they suck badly. Please allow yourself to grieve. Allow him to see that you know or think it is over. It will either show that the relationship is really over for good or bring him back begging for you. He knows he has you when he wants you so he isn't going to care to work at it...if you start acting like it's over and he's really not ready for it to be over...call his bluff...he'll be back on his kneesf ro you with gifts and all the great things ready to work at it again. What have you got to lose at this point?