What food causes tooth pain?!

I have been brushing teeth all life, I experience pain to hot and cold water and food. I'm a teen. The teeths hurt sometimes when I eat something solid. What food causes pain? Is that meat, grain or sweets? I have some serious problems with teeth, obviously my teeth is damaged. How can I reduce damaging the teeth? I eat sweets very rarely, once in a year. I do eat meat if served. I don't like too much grain, I eat little or no bread with a meal, I don't eat whole bread nor I eat a lot of grain.