((((((Dagny))))) I think mishka said it... talking with him, trying to understand him, it's not going to help at all.
I know you have a deadline, but that's only a deal between you and yourself. The way he is hiding money, I think I would seriously consider starting to take action now. I am concerned that he is going to leave you high and dry, and without the means to protect yourself. Anything you do now is not really going to do anything negative to your chances of a reconciliation, if there are any chances. If anything, you taking action is going to perhaps get him to realize that there are going to be consequences of his actions.
Withdrawing from the world, in the short term, maybe not so bad, but you are right, in the long run you don't want that.
