Hayley,
Sounds like you might really be in love with this boyfriend of yours. It seems like you've really tried talking things through with him to figure out what the deal is, but I believe there is a problem. I think your boyfriend might still have feelings for his ex; maybe there is something she has that you don't and he's still remembering those times with her. What you need to do, no matter how much you love him is tell him, "Baby, I'm sorry...but I really can't stand to think that you still have feelings by your ex and I'm continually being hurt by that fact." If he doesn't feel bad and apologize, then I think you should take a break. Maybe play a little hard to get. That game is really hard to play, but it will make that boy grow in respect for you. Boy's respond to what they don't have...so swtich things up a bit. If he's being disrespectful then he really doesn't appreciate what you two have. Make him appreciate it. Stay single, don't hook up with anyone. You don't even have to break up. Just become more "preocupied" and busy when he wants to hang out. Stop calling him and when he calls you either don't answer some of the time, or only on the third ring. He will be begging for you back and realize, hey... I can't get this girl that easy. Trust me, it is very effective. It's hard to do when you are in love with someone and you really do want to be with them, but you have to in order to keep this boy interested. Good luck.