Sorry to hear about the accident. One thing that makes me more angry than anything in this world is a doctor who will not control the pain of a chronic patient, especially one who's injured limb is infected with an incurable condition like RSD! Why do you need this doctor to release you? If it were me I'd release myself if push comes to shove. I'd explain to this doctor that he is failing to control your pain which is a direct result of a chronic condition and a injured limb in an accident and that you demand the pain to be controlled now because it is your duty. If you can't speak up then get a loved one to tell him. If you get no results then tell him you are filing a complain against him and then move on.
I hope you get relief very soon!