IRS gave my money to pay a debt, my Ex is $3000 behind on his child support, how can I get my return?

My husband and I divorced last year, January 20010, we filed our taxes jointly since we were still married in 2009, we were sent notification that our refund was going to go towards some "unknown" debt. I filed a injured spouse and they sent me my portion of the return. This year I am filing the first time head of household, I have 2 children I support on my $13000. annual salary, my Ex is now $3000 behind on his child support and the IRS sent me notification this year stating they took my return for a debt. I have a contract with my landlords that because I am financially depraved and my ex's inability to pay in a timely manner, or at all, they would wait for my tax return to be paid the rent due for the whole year. I need help because now I owe them rent and IRS sent my return for this debt, I have no way of paying my landlord! I am not sure how long they will be generous enough to allow me and my boys to stay in the house without payment, I filed papers for an adviser and they said they cant help me. Is there some sort of hardship form or something to explain my plight so that I can get my return? and will this effect my receiving my Ex's return, should he file, for the child support he owes me? Thank you