Should I stay with my boyfriend? I am so confused and heartbroken. Please help!?

Move on. Honestly. It is for the best and would be healthier for both of you. Love isn't this difficult or complex. Relationships can be hard but not love. He wasn't lying to you but he wasn't telling the whole truth. Fact of the matter is he doesn't know what love is and said "ILY" when he was still in the infatuation stage mistaking that for love. He is not ready to give you the relationship you want and you going abroad to study means you don't have the time to cultivate a relationship with him. Move on. Enjoy your time abroad, have fun, LEARN and put him out of your mind.