Thanks for asking the query,
As described by you , your wisdom tooth had become badly carious .
This area is very difficult to clean so it often invites bacterial infection leading to redness
, inflammation and swelling of the surrounding gingiva
The tooth had become carious there is infection of the surrounding tissues and abscess
You need to visit Oral and Maxillofacial Surgeon and get checkup done .
Take an x-ray of the tooth, most probably the treatment would be extraction of the tooth .
Take complete course of antibiotic and analgesic
Use saline water gargles 3-4 times daily.
Use 0.2% of chlorhexidine
mouthwash gargles twice daily .
Hope this helps out.