what might be wrong with my tooth?!

Why would a dentist fill a wisdom tooth? Geez man, greedy people.. Your mouth is generally too small for the wisdom teeth, so you cant really brush really good back there. If you had a silver filling, then it must have fallen out and wasnt done very well. If its a white filling, theres a good chance you have recurrent decay, which led to a bigger cavity under your filling, which means it got to the nerve, which means its hurting. And that type of decay could result in an infection, youll need an x-ray to be sure, but just get them out. alot easier