In a long distance relationship but he's acting weird...?

I've been in a LDR for about 2 months with my boyfriend. I only have 2 and a half weeks of long distance left before I go back to college and will see him all the time. lately though he acts very distant and doesn't have much to say. He doesnt say "I miss you" or anything affectionate anymore. I asked him a few days ago if he would be available the day I'm moving back to school to help me and come hang out, and all he said was "I don't think I have anything planned for that day". today I asked him if maybe we could go to the beach after I come back, and all he said was "such and such a place would be the place to go." He didn't seem excited or enthusiastic about that idea. He still texts me daily but his texts seem so uninteresting that I just end up getting annoyed at him and question if he still likes me or if its just the fact that we haven't seen each other fro two months. advice pleaseee??