Should I break up with my boyfriend?

Together 7 months. In the beginning he pursued me: he sent sweet emails, took me on dates, sent me flowers to my work, and always said the SWEETEST things to me. After one drunken night, I remember him carrying me to his bed, brushing my hair with his fingers, while,spilling his guts out about how much he liked me thinking I wouldnt remember, then he slept on the floor bec. he didnt want me to feel uncomfortable when I woke...I pretty much fell in love with him right then. And we've been together pretty much since then...Now, for the past month I feel like he isn't interested anymore...when I hang out with him and his friends I feel like I'm on the other side of the world, when I'm out of town he calls me once a day and we only talk for few min, i can't stand laying next to him with is back towards me, he isnt sweet anymore. I confronted him two weeks ago and he agrees that he has been diff, he doesnt know why, but he still loves me. I don't want to lose him but I'm tired of crying