The wisdom tooth must have erupted around 18-21 years but now that it got impacted it has to be removed. I suggest you get it done immediately before it starts damaging the adjacent teeth.
Next Steps
Refer to Oral and Maxillofacial surgeon.
Health Tips
Don't worry about pain, nowadays most of the procedures in Dentistry are painless. You might be having post operative swelling after surgical removal of wisdom tooth. Use warm saline gargle till the time you get it removed.