from what you have mentioned, it seems like you have a sensitivity problem or one or more of your teeth might have a deep cavity. Sensitivity is usually caused due to recession of gums (gums moving down and exposing the root, teeth getting worn down due to vigorous brushing. I would advise you to start using an anti-sensitivity tooth paste and get
a thorough dental check-up done.
If you wish you can consult with me for further help.