Happened to me as well. Tooth got infected so bad that OTC painkillers did not work anymore. The anesthesia made the painful area smaller, but could not eliminate it entirely due to the acidity of the infection. Still, it was much better than the pain from the infected tooth.

Go to the dentist folks. And if you are afraid of them, like I was, find a very kind one and get help before the pain forces you to get over the fear.