HELLO AND WELCOME TO HCM FORUM ,
according to the dental history provided by you it is clear that your lower left wisdom tooth has not erupted fully, it is impacted.
Therefore ,in such cases a gingival flap usually covers the tooth partially, which gets inflamed and infected with the food debris, causing pain.
Sometimes, impacted wisdom tooth
, due to its abnormal placement in the jaw can impinge or exert pressure on the sorrounding nerve
supply, causing severe radiating pain
I advise you to visit an oral surgeon soon, he/she will click x-ray of your tooth and accordingly plan a treatment.
kindly perform warm saline rinses(3-4 times/day), you can even use an antibacterial mouth wash ,twice/day, this will take care of infection and swelling if present.
i hope i answered your query,
i wish you good health.