Boyfriend off a long time

I've been with the same guy for a year and half now and we use to be really close but things don't seem the same anymore. We've both recently started college (his being local and mine requiring lots of travel) but since I've started my new course (a week after his) he's been acting really funny. My new friends are convinced he's cheating been so he no longer lets me on his phone anymore (he use to ask me to read/send texts for him) but I'm not sure. He's usually really sweet and caring but lately he's been the complete opposite, even insulting my new friends (who he's never met) I don't know what to do, I don't want to end it but everything seems to be going wrong, HELP!!

his defs up to something. you need to confront him asap. i understand how hard it is to let go if that's what might happen but you cant let him lead you on.