Pour a shot of bourbon.
Hold it in your mouth over the sore.
It will hurt for a moment. Keep holding it.
After two or more minutes, consume the bourbon. Smile.
Hey, it worked on an abcess where my wisdom tooth used to be.
Salt/salt water, aspirin/ibuprofen, etc.
You have my sympathies. Perhaps a visit to the friendly apothecary or medic is in order?