I have been experiencing extreme pain in my right upper arm. It ranges from my shoulder to above elbow. I cannot move my hand behind my back or raise it to put it on my other shoulder. It started 3 months ago with little intensity but now it has been increasing gradually that now I can't stand the pain while doing daily mundane jobs. When started, the pain stays for 10 minutes straight. When staying still, sometimes it seems as if my arm would fall off. Please help. Thanks.