Aaahhh....the old fight about money thang...its usually never about money, rather something else. Its seem like money is a symptom of a larger underlying problem. You said he is afraid that you will leave him, do you threaten him with this?

Do you guys have a time limit on how long you will talk. Say you get 5 minutes to express yourself and then he mirrors back what you said, if he misses a point,you share it with him again. This way you feel heard and he knows how you feel without you blowing a gasket, then its his turn.

It takes work at first to mirror and reflect, but if you can master this, you guys will have a lot less conflict in your relationship.

Good luck!