Regret to hear of your problems. Clearly you have asked two questions on the board.
In response to the 3 months coming out of your share of profits, you will have to decide
whether it makes business sense to hire a lawyer or take you ex to small claims court.
Generally lawyers charge $250 to $500 an hour and it will take at least 10 plus hours to handle your case.
Check whether you can work it out without an attorney. However, if you need one, I know a real estate attorney that I can refer to you.
You say ex-husband. If you are divorced you should contact your divorce attorney as to what you and your ex agreed to in the divorce.
Escrow can not close without making sure everything is cleared from title, this includes late fees, property taxes, etc. As to the division of those it would be in your divorce papers or as agreed to by you and your (ex)husband.
You have options, and those options would be addressed by an attorney.
It sounds like you need to consult with your divorce attorney as to who was responsible for making the mortgage payments and the outcome of the split.
Yes, as the others said, you need Attorney. This is a legal question. Also much more information is needed.
I recommend that you schedule at least a 20 minute interview with several Attorneys, to decide not only whether or not you wish to pursue the issue, but also which Attorney is best for you.
At your service,
Certified Distressed Property Expert