I had a kidney infection about 18 months ago. They diagnosed it as backache first, and made me rest with a hot water bottle against it... which made it 10x worse. By the time I went back to the doctors, I could barely walk and nearly passed out in the surgery. I've never known pain like that.
I used to get ear infections every year when I was little too, and they hurt so much that I used to cry until we went to the doctors. I still get the odd twinge in my ears, and it feels like someone's shoved a knitting needle in my ear. Ow!!
Hope your tooth gets sorted soon Pebbles.