You may have success in a small claims action against the former landlord - but I would weigh the effort to do so against the possibility of collecting, even if you are successful. The law enacted to protect tenants was designed with people like you in mind. If I may suggest - contact your representative who gave you an agreement at Fannie Mae and ask them about their cash for keys policy to help you recoup your deposit loss.
Best of luck!
You could file in small claims court yourself. The clerk at the courthouse can tell you how to do that.
You are better to find a stable location first and deal with the deposit later.
Good luck to you.
Sorry you have encountered this situation.