It might be a decayed tooth if some food particles stuck there it might be infection. You can use the following medication to reduce swelling and pain
Tab. Augmentin 625mg 1-0-1 × 5days after food
Tab ketrol DT 10mg 1-1-1 × 5days after food
Tab pan D 1-0-0 × 5days before food
Next Steps
1. visit dentist as early as possible
2. do warm salt water gargling 5 to 6 times a day.
3. medication is only for temporary pain relief for permanent solution visit a dentist.
4. Donot use medication for more than 5 days if pain doesnot subside or increases visit a dentist.
5. if found any allergic symptoms stop the medication and visit a doctor.
Health Tips
its always helpful if you attach pictures . you can consult me in my private chat with pictures for proper treatment plan