The symptoms are usually associated with impacted wisdom tooth
which is inflamed.
Since you are at the age of 30,and the tooth is decayed,mostly tooth has to be extracted.
Take complete course of antibiotics and analgesics.
Rinse your mouth after every meals.
Gargle using lukewarm saline or betadine
Please do visit a dentist
as soon as possible.
Maintain oral hygiene
Avoid anxiety and stress.
Hope this helps.