Firstly I would say that pain doesn't subside by anti sensitive tooth paste.so it is of no use to you unless you have sentivity.   As you mentioned that something has hit your tooth that clearly suggest some trauma to the tooth and the surrounding tissues. You should visit a dentist and get a clear openion on it. Any pain killer will not cure the problem but yes it can surely give you temporary relief..

Dear patient. 2 years is a long time to have dental pain. Your tooth might be affected by dental decay. An x-ray sometimes be needed to confirm the same. U might need to get either a filling or a root canal. That will solve the issue.