There is not enough detail in your question to give a complete answer.
The best response is a suggestion that you get in touch with a local mortgage professional and discuss your situation.
I suggest that you speak with a mortgage broker or even your current lender regarding refinancing. You may have to do a "quit claim" deed to remove your ex off the mortgage.
It's best to speak with a lender as they can advise you best on your options.
Prudential Connecticut Realty