unexplained numbness

i could give you a fairly detailed medical history but these are the basics, i have a family history of diabetes and work with computers a lot, and do have a job with repetitive wrist movements. so here is my problem, when i stretch my arm out in a specific way and turn my wrist i get a fairly severe pain just up my arm from my wrist, it feels like a tendon being stretched way too far. but i recently noticed i now have no feeling in the skin where i also have the pain. am i tearing nerves somehow? i recently started working out and this only made me notice the pain more often, i don't think its making it worse but allowed me to notice the exact circumstances to duplicate the pain.