Don't panic! This is one of the complication of wisdom tooth extraction.
Apply ice-pack 2-3 times on that region.
Apply T-Bact ointment on the injury 3-4 times a day and keep the injured area clean before applying the ointment.
Apply Dologel ointment inside your mouth at injured region 2-3 times after meals and after rinsing your mouth.
Next Steps
Take Diclofenac sodium+Paracetamol combination for pain & fever twice a day for 5 days.
Antibiotics twice a day for 5 days.
Health Tips
Do warm saline rinses 5-6 times/day for 2-3 weeks.