I had a cavity on the second to last molar on the upper left filled/refill back in Oct. as well as one on my lower left. I went back because the bite felt wrong and it seemed like I was putting pressure on another filling in the incisor. It was adjusted but the bite still felt off, figured I'd get use to it. About a month ago, my upper left from the incisor back start to hurt whenever I ate and it was difficult to pin point the exact tooth. Then two weeks ago my gums in that area bleed when I brush my teeth, no matter how soft I brush. I am really afraid of losing any of my teeth. Am I overreacting or is this something serious?