OK, unbelievable that I didn’t think of my mother’s relationship before, but here goes.
My mother had a relationship with a man which was quite similar to what you are describing (with the difference of this not being a marriage and arguments not being about the money).
This man did agree with relationship counceling, but once there he wouldn’t really cooperate and often just left. He also often threatened not to come along.
He was also quite the narcist, and used to have mysophobia. Though the latter had been diagnosed as “cured” some twenty years ago, he definitely still had/has a form of it. In short: he was really hard to live with.
This carried on for several years (I think about five years that he had been living with us), and though they argued quite a lot, my mother also was a fixer and thus tried to, well, fix it. The problem was that he did not cooperate.
A little more than a year ago, the relation ended, and he moved out without even saying goodbye.
The important part of the story is what happened afterwards, to me. I was an extremely quiet, introvert person and did not really socialize. However, I had never realized this might be because of him. In the last year, I’ve noticed a tremendous change and I’m not the same person I was a year ago. It really changed drastically for the better.
So I guess the moral is that, for the sake of your children, something needs to be done before they are affected in their development. Something like this can have a tremendous effect. If your partner really does not want to cooperate, I’m afraid the best option might, indeed, be divorce. However, be sure to have him know this, too.
Unfortunately, I cannot really give reliable advice on how to fix this marriage, since my mother’s relationship did not work out as well. However, I do hope my story shows that something needs to be done.
Best of luck.