ADVICE ON GETTING OUT OF THIS DEBT HOLE!?

We bought our house 4 years ago but if we sold now we would only make 4 thousand as house prices hve fell!we need to do something as we cant afford the mortgage and all the bills anymore,i work part time and mu hubby works all the hours he can as a taxi driver where the money is rubbish as he has to pay 450 a month just to rent his car and ins! we hve 3 young children and are struggling more and more each day what can we do to get out of this mess?there is no other jobs for my hubby we keep looking and we cant sell r house to buy another as we r in negative equity!HELP!any advice appreciated