To put it into perspective. You are only liable for JOINT loans and financial commitments. Even if you are a second card holder, you are not liable to his debt and will not carry is credit worthiness on your record. You can contact the credit history agencies and check your record to be sure.
I would advise CCCS for help and advice but obviously he has to talk to them. He does sound like he is sticking his head in the sand and hoping it will go away, which I am afraid is the attitude of many people so he is not alone.
However, and I dont mean to sound harsh, but how on earth did he get so far into debt without your knowledge? What has he spent the money on?