Hi Jim - Sorry to hear about your difficulties.
Who is your lender? More specifically, who is servicing the loan, the company you send your payments to? That's who you need to contact and soon. It may or may not be the same company that gave you the loan, but they're the ones who are in a position to approve any loan modification. Their contact information will be in your loan statement and they are required to put you in touch with a person who will serve as a single point of contact for discussing a modification.
The following gives some general information about obtaining a loan modification. Note that the federal HAMP program is no longer available, but most of the information still applies.
If you need additional help, check with a HUD-approved housing counselor in your area - Google "HUD housing counselors" to find one near you.