My upper arm hurts every time I throw. Do I see general orthopedist?

Depends. If it is short term rest and local therapy (heat, mineral ice etc) may be reasonable. If it lasts more than a few days without any evidence of improvement then seeing an orthopedist would make sense.
Sports medicine. If the symptoms are such that you want to see a physician, i would recommend a sports medicine doctor. They are initially trained in a variety of residency programs (orthopedics, internal medicine, family medicine) and then do a subspecialty in sports medicine. They would be a good place to start and would be especially trained in understanding why you have pain with throwing.