As with most things in life, the answer is, "It depends." Why do you want to sell now? Could you just grit your teeth and hang in where you are for a year or two until your home value comes back in line with what you owe? (Also taking advantage of the time to make inroads on that pesky mortgage balance...)
If you really need to move now, your best option might be to rent out your current home for a couple of years. The rental income to you would cover or mostly cover your expenses of owning the home, leaving you free to move somewhere else. You might or might not be able to get a mortgage to buy another house right away, but if the expenses of this house were covered, you could at least rent somewhere else and buy after you can sell later. Who knows - you might even be able to sell the house to your tenant later!
You do have to be careful about leasing or lease to own programs - be sure to seek the advice of a professional REALTOR on how to structure any program.
Good luck! It's no consolation, but you are far from being alone in your situation....