Is it time to let go?

My boyfriend and I have been together for 2 years now and had the most amazing relationship with him, he was everything a girl could ask for I mean EVERYTHING. Lately, though, I feel like he's pushing me away and becoming strangely colder to me, like ignoring me or something. I love him so much there's no words that can properly describe it, but when I try to understand his side to all of this, I'm in doubt. This is our last year of school and we need to work our utmost hardest, and this could be a contributing factor to his reactions, but I'm in the same boat too. I too have enormous amounts on my plate but no matter what I will put him first because he's my priority. I've tried talking to him but everything becomes so much more worse, despite the fact that I'm not the type who expresses themselves I'll still try to put an effort into solving things and talk about my feelings which I don't feel comfortable doing, but still do for him. We've tried to take breaks but we end up coming back to each other the next day. I try to overlook everything he does that upsets me, but I just feel so hurt and cheap. As much as letting go is going to destroy me, I feel that sometimes I want a fresh start, we've been through a heck of a lot together so everything is so deep between us. I want the old him back, the caring sweet romantic loving understanding big hearted him. Not the busy cold guy. Please give me your advice on what I should do