foreclosure and equity

i bought my fha home in 1993 when i was alone and a single parent. the house was in my name only. i got married in 1996 and his name was never put on the house. our divorce was final in nov 2007 and his lawyer had papers drawn up saying my ex is due$17,500 in equity in the house either when i sell it, refinance it, or when my daughter turns 18 in 2015. well i am disabled and unable to work and having to move me and my kids in with my parents. i am unable to fix the house up good enough to sell, my credit is too bad(because of my ex) to refinance and if i foreclose on it, i think i have 90 days to pay my ex $17,500 in full or i will go to jail. i had this house 3 years before i even met him and i made most of the payments. i have no idea how i am supposed to come up with that kind of money to give him. he has since remarried and if something happens to him, he will give her the money. please someone out there, i need some advice on what to do. i dont want to go to jail and i am a good decent person just trying to take care of my kids. i also cant afford a good lawyer right now. i would appreciate any advice yall could give. thanks