I would suggest that you contact an attorney who specializes in consumer protection law who can review your loan documents. I would NOT sugggest that you contact a real estate attorney. You can find an appropriately credentialed legal eagle at http://www.naca.net.
This attorney may be able to find a deficiency in the paperwork that will give him/her the leverage to negotiate a solution that best meets your needs. By all means, do NOT rush to a short sale expert. Many short sale experts are driven by income goals that do not reflect a homeowner's true needs.