It sounds like your have a two part question - one dealing with home price value fluctuation, the other having to do with possibly being behind on some payments.
If the situation was just one of the value being "upside down", but with affordable payments and a roof over your head, is the home still the home you purchased thinking you would be there for some time? Or, did you buy it thinking you'd be able to refi or sell for a profit in a short time? What changed in th elocal community to impact values so much?
The second part of the question - what do do when you are upside down on value and behind on payments is the challenging question. Local real estate market conditions may determine what value a lender would put on the home today. Selling the home, even in a "short sale" with lender approval might cost the lender less in losses than if they foreclosed. Modifying the loan to give you an affordable payment and let you keep the home might save the lender even more money and save you money too.
This isn't really a quick and easy question to answer over the computer for you. You may need the advice of a good real estate agent in your area and/or an attorney, tax accountant, etc. to figure out your best course of action.
CENTURY 21 Alliance