(((Jo))) You probably don't want to hear this, but I feel that something isn't quite right also. Can't exactly put my finger on it though. Could it be that he comes running back to you when he's "between" women? Can he not be without "somebody"?
I do wonder why you think you'll ever get what you need from Andy. He just doesn't seem to "get it"....period. It's always all about him.
You were doing better emotionally when you'd decided to move on. I suggest you adopt that attitude again. As I mentioned before, he wants you when it looks like he can't have you. My hope is that eventually you really won't want him and your life will be peaceful and happy.