I think that I am going to take a chance and be really honest with you here, though please know I am basing this solely on what you have said about your relationship, so I obviously don't know everything that's going on:

That being said, I have to say that I think you have already made up your mind about going without him, but you feel some need to "make sure" you are doing the right thing. As much as it sucks, you two just don't seem to be on the same page about things and it seem to be a situation where your opposite traits are not complimentary. Perhaps if you and he were more balanced together, things would be alright, but it seems as though the traits he exhibits are things you don't like. From my own personal experience in several long term relationships you have to know that you can never change another person. And if you did tell him he's got to change to stay, he may "change" for the time being, but he's only doing it to keep you, not out of a genuine desire to be different. The only person you can ever induce to real change is yourself. Its likely if he "changes" that all he will do is revert back to his old ways once he feels comfortable again and not on notice that he's going to lose you. I'm not saying its not possible for him to genuinely change, but if he does the desire to change is going to have to originate within him and be his decision.

I hope that I didn't offend you by being so direct, if I did, I really apologize. I want you to be happy.