I would suggest seeing a chiropractor, preferably someone that practices the "activator" method (long story, but mild yet effective manipulation technique). The bones being out of alignment can lead to many nerve-related problems. It is quite possible that the weight of your head and the laxity of your sleeping hand combined to pinch a nerve. He (or she) would also be in a position to direct you to other help.
I would suggest seeing a chiropractor, preferably someone that practices the "activator" method (long story, but mild yet effective manipulation technique). The bones being out of alignment can lead to many nerve-related problems. It is quite possible that the weight of your head and the laxity of your sleeping hand combined to pinch a nerve. He (or she) would also be in a position to direct you to other help.