You should view in the mirror if there is any black or brown spots or catch is there. Pain could be because of Dental caries.
Taking Painkillers won't solve your problem permanently.
Next Steps
You should visit to a restorative dentist or an Endodontist so that he can diagnose and treat the exact problem with his/her expertise.
Health Tips
Don't sit back at home and take pain killers till the pain subside.