79 hours after wisdom tooth extraction. is it normal to have a stinging pain ? what are the chances of me getting dry socket?

Sorry but: There is no good answer that i could give you over the internet. I suggest that you continue to follow your dentist's instructions, take some otc pain medication such as advil, motrin, aleve (naproxen) or what you would take for a headache; call your dentist and ask to be seen for post op evaluation. Perhaps he\she has a 24 hr emergency answering service.

Pain not normal: 'stinging pain' surely sounds like more than would be expected. I would call the on-call dentist to discuss with them.