You are way over.
The ';better it gets the more he pushes away'; thing is a great line to feed to the current girlfriend when he wants to get rid of her. It engenders feelings of sympathy, so you won't create a scene and make him feel bad for dumping you. Instead you go away thinking, ';oh poor baby';. By telling you that you may be the one who 'fixes' him he is managing to keep you on the hook until something better comes along. Tell him that he is full of s**t, and dump him.
Your chest pains are symptoms of panic attacks. You do not cope with stress well and there is a hell of a lot of it in your life right now. Go to your doctor and ask for a medication to help you cope for a while. You'll feel a heap better, and it does not have to be a long term thing.Words of advice?
I hate to tell you this - not only are you over - you probably never were. It's fantastic that you are working on yourself %26amp; your isssues - but you can't ';fix'; him, he needs to do that, and until he does he won't be able to have a close relationship with ANYONE, so don't take it personally. You need to end this and find someone who is emotionally available.
Knowing is better than wondering. You will be never able to overcome your issues if you live precariously. Talk to your boyfriend - that would be a good start to deal with your problems.