Hello,
You may have these symptoms because of teething or eruption of the wisdom tooth. I guess it should be the erupted upper tooth rubbing against the gum surrounding the lower erupting wisdom tooth. Treatment depends on the space available in your mouth for the eruption of the tooth .So visit a nearby dentist for further management.
Next Steps
Add a little amount of salt to Luke warm water and do mouth rinsing for 2-3 times a day.
Health Tips
visit a dentist. Best regards.