I have pain where wisdom tooth used to be, please help?

See a dentist: See a dentist in order to determine the cause of your pain. It could be lot's of things, and most likely from an adjacent tooth or canker sore.

See oral surgeon: Best bet is to see an oral surgeon. Often the tooth in front of the wisdom tooth has a cavity. there could be a piece of bone or tooth from the wisdom tooth extraction coming through. Plus other causes. See oral surgeon.