Priorities. Does the job have health care and stuff like that? If it has good benefits, that's worth a fortune...... and to have such support from his boss.... hard to leave a comfy groove.
If hubby can cope better, and family basics are being covered, is more money necessary?

Could you consider this a breather on his part and look ahead to a time when he might be more willing to consider moving on, and refocus on you. He's going through what he's going through and can't be pushed, changed to do it "your way".

Could you maybe get down with yoourself and make lists: get clear about what you feel more money would accomplish. Once it's down on paper, your head may calm down a little. Get creative and refocus away from what you can't do into the world of what you can do.

You are the only person you can use your will on to make changes. When one person changes, the whole picture changes and we never know how it will turn out, we just know it will move.... All we can do is our part as best we can and (as hard as it is to watch) assume others are doing their best too.

In the meantime, throw ice cubes against hard surfaces.....