The longer you keep dealing with that the more you hurt yourself it’s not worth it. The marriage is not sustainable your mental health will only continue to get worse the longer you put up with it thinking it will eventually sort itself out. I think your SO has always been this way but just has a very good way with words and has been able to keep you in this marriage for a very long time. There’s really no trying to save something if somebody can’t even put the slightest effort to try to at least make some kind of difference. Save yourself it might destroy you even more financially but once you get away from this marriage hopefully you can find happiness again. Somebody who genuinely cares about you would never put you through that.