to forclose or not to forclose

ok, here's the situation. my girlfriend and i bought a house together 4 months ago. she put $10,000 down and I put 0. now we broke up and she doesn't want to sell in this market because she won't get her $ back. i can't get off the mortgage because she can't refi by herself and neither can i. we can't get co-signers so i was considering leaving and letting the house go into forclosure. my question is will i be considered insolvent by the irs if the house gets sold and we owe the difference tax wise. i take home 2400/month. i have 0 savings...a few hundred in checking. my mortgage is 900 and bills are about 300; car is 380, insurance is 100, student loan is 133, gas and food another 200. i owe 8,000 in credit cards. please help!