Child Support if my son is in Juvenile Correction Facility

My son has been placed in a Juvenile Correction Facility for the next 18 months. His father immediately stopped paying child support. I still have to make payments for to my son's attorney, pay for medical insurance and pay $175 per month for detention, not to mention court costs. He claims he is now not obligated to pay child support since my son no longer lives in my home and as for the rest of my son's obligations I'm on my own. I asked the Probation Officer to add my son's father as being obligated to pay half of the detention costs, but she has ignored all of my requests. Is there anyone else I can get help from to help me get my son's father pay his half? Or could I get the detention fee reduced since my income is low and if so, who do I contact? Hopefully not the Probation Officer.