The reason i asked about your work and activities is that there is a condition called Thoracic Outlet Syndrome {TOS} , often due to repetitive type jobs, or certain injuries {whiplash etc} that can cause hand , arm, nerve pain - but it usually has neck and upper back pain or discomfort with it.
You may want to read on our TOS forum to see if it fits at all or not. Check the useful sticky there too - various therapy & treatments mentioned that might work for all causes of pain -
http://neurotalk.psychcentral.com/forum24.html

I just think your dr/drs isn't listening to you & your pain - people do have differing pain tolerances IMO.

Keep looking for one that will care and listen to you.
Has any of them sent you for PT evaluations? By an advanced therapist of cousre.
sometimes the PT places can suggest a good dr