Should I short sale, ask for deed in lieu or rent my home?

My husband and I bought a brand new townhouse in Homestead, FL. We would like to move to TN before the end of the year. Like a lot of people we are upside down on what we owe (120k) and what the house is currently worth (70k). We've had the house on the market for 3 long years and havae had 2 contracts on the home that fell through due to buyers not able to obtain financing for the full amount that we owe. We don't have the difference so we cannot sell the home for less. We are current on our pymnts and both my husband and I have excellent credit (700+ an d 800+). We've been trying to do things without ruining our credit or missing pymnts but we'd like to move asap. We've looked into short sale, deed in lieu and renting the home. We are terrified of stopping our pymnts and ruining our credit and losing all our credit cards but we see no other option except renting. Were also scared that if we rent the home and the renter leaves or stops paying rent we'll be left paying 2 mortgages instead of one. Any ideas on what would be a decent solution to this dilema?