The only way to stop it now is with a Chapter 13 bankruptcy. You need to act fast. Get a bankruptcy attorney, explain the situation, and have the attorney call the Trustee and tell him you're filing for Chapter 13 today.
A Chapter 13 can halt a Foreclosure immediately (up to a minute before the auction begins if the Trustee is notified in time). This will give you some time to resolve the situation with the lender.