I was in a similar situation, boyfriend had to move to another state to start university. 3 months later the same thing you are going through happened to me and i found out he was cheating on me. However just because it happened to me, doesnt me it will happen to you.
Just tell him that you need to talk, ask him what he wants from this relationship and if it is working out for him. Like your friend said, he might be going through something with work and school, so he might be stressing a lot. Not all guys are a-holes.
Just give it time, and if you feel something is wrong and he isnt opening up and you cant go through with the relationship, then i guess you should end it.