hi and welcome ,
Your history suggests after the dental treatment done on your teeth you may have developed allergy
to the lip mucosa by the medicaents used during reatment like irrigating solutions or eugenol , hydrogen peroxide
or even the rubber dam applied for isolation .
Rubber dam is made up of latex and some patients are allergic to the latex and the denntal materials used for treatment.
i would suggest you to consult your dentist
and talk about the allergies.
your upper lip
seems to be inflammed , you can apply dentogel oral antiseptic ointment topically over the area .
you can start with antibiotic amoxycillin
with analgesics two times daily for 3 to 5 days which will subside the swelling and relive pain .
i hope this helps ,