The pain is caused by either bacteria (most likely) or an exposed nerve (less likely). The bacteria have been able to invade your tooth because it is weak. It is weak because you are mineral deficient. Get calcium supplements ASAP and start taking them immediately 300% recommended daily dose for a few days then lower to a more reasonable amount when your teeth feel stronger.

To fix the bacteria, ideally you need antibiotics such as amoxycillin or erythromycin. Colloidal silver can be helpful too if you have any.

Brush your teeth. Use an antiseptic to brush with like hydrogen peroxide (diluted), alcohol, mouthwash, bicarbonate of soda (baking powder) will work well to kill bacteria as they require an acidic environment. After you have done this, make some warm salt water (fairly salty) and hold it in your mouth for 10 minutes or so. Repeat every so often. Drink only water.

See a Dentist. Don't use fluoride. Don't allow them to put fluoride on your teeth, fix your mineral deficiency.