I had a surgery to remove melanoma, 2 years ago. it was in my upperarm. now i'm having bad pain in my arm right arm and can barely lift it. i also have factor 5. what should i do?

Melanoma arm pain: You need to have your pains evaluated by a physician. Its unlikely, if you have been having regular follow-ups, to be related to your melanoma.

Could be recurrence: If the question is whether this might be a recurrence, then yes, the new onset of pain and weakness can be a recurrence of the melanoma in either the arm or the lymph nodes. It is important you be seen by your surgeon or oncologist to rule this out.