However before you walk away, if you have a hardship as you explain in the question. It is very possible that your lender would approve a short sale of the property.
I recommend you find a Real Estate Agent in Florida that is an expert on Short Sales and working with banks. I would also recommend you setup a meeting with a CPA and discuss with them the possible TAX ramification of both Short Sale and if you walk away and let it go to foreclosure. Both situations could cause you to owe the Federal Government income taxes.