what should we do?

We are seniors on a fixed income having difficulty paying our mortgage. Our mortgages total more than the house is worth. 1st mortgage is $117,000 and our 2nd is $20,000.according to Zillow our home is worth $113,000 but with the improvements I figure closer to $120,000. We are current with both mortgages at this time. We filed a chapter 7 about 18 mos ago and signed a reafirmmation on both, but the company who had the 2nd did not file the one we signed with them. They sold the loan to a loan servicing company.The loan servicing co said no afirmmation is on file. What will happen if we only paid the 1st mortgage? Should we walk away from the mortgage since we can't afford it? We really don't know what to do? We are at a loss in knowing how to go about letting the house go into foreclosure and what will follow the foreclosure?