well you know what to do about
mental issues of anxiety...get some meds to help with the withdrawl, this is quite common when weening off of narcs (make sure you tell the psych doc that you are weening off narcs, there are some antianxiety meds that can really help with pain management as well)
Do not forget to try just some common sense stuff like put a cold pack on it. But seriously do not withdrawl from narcs without help. It will take weeks under the best of circumstances.