Thanks for asking the query,
Swelling in the cheek and pain is due to the wisdom tooth, this area is difficult to clean often invites bacterial infection leading to readness, inflammation and abscess
formation is required, if not treated in time can spread to the tissue spaces.
I would encourage you to visit the Oral Surgeon take an OPG radiograph and plan for the extraction of the wisdom tooth.
Take complete course of antibiotics and analgesics.
Take antiseptic mouthwash rinses.
Donot delay the treatment.
Hope this helps out.