I was hurt on the job in Dec. 2008, haven't worked since, I kept up with my CT court ordered support for most of the time but recently got behind about $5500 while I was waiting for the SSDI hearing. I was approved for SSDI in Oct. 2011. Now, my sons mother is going to get $735 a month and a lump sum from back pay of $20,000. I was paying $460 a month priour to my approval. Will the $735 a month from SSDI take the place of the $460 I was paying and will the $20,000 go to cover the arrearage.