Hello Mam ,
First of all for instant relief you can take Tab.Zerodol -SP (SOS)
Along with tab.vit-c + vit.
B12 capsule .
Next Steps
do maintain yours oral hygiene and for swelling and pain you can go for the gargle of salt + warm water.
Health Tips
anyways these above mentioned points are likely for home remedies , but still you need to go to a dentist for proper examination and treatment,
might be possible you were suffering from any problem of unknown origin as your description about pain and swelling was just not enough for diagnosis.
thanks and regards,
Take Care.