To start with, try to use a special toothpaste like Sensodyne or Colgate Sensitive. Most of the times using for a week can solve the problem. If the problem persists even after 2 weeks visit your nearest dentist. Try and avoid too cold or hot food for the next week.

Tooth sensitivity is due to many reasons like deposits, cavities, gum recession etc. For giving a proper treatment we need to know the exact cause of sensitivity. For time being you can start using anti sensitive tooth paste. But you do have to visit a dentist for removing the cause of sensitivity. Also you can avoid too hot or too cold stuff till your problem gets solved.

I think your tooth is decayed  thats you are having pain if you consult a near by dentist then depending on the status of tooth either tooth can be treated rct or it has be removed