If you have severe pain, you have to get a check up and probably an x-ray done for that tooth. The pain could be due to very deep cavity. Please consult a dentist ASAP. For temporary pain relief you can take any pain killer which suits you.

As per the description it seems the tooth is decayed.

You need to visit a dentist as soon as possible to evaluate the exact current situation of the tooth. The treatment can vary from a simple filling to root canal treatment followed by a cap. Regards.

Hello sir As you complain of pain, which means that filling should not be done on the tooth which has pain. Pain is usually indicator of infection. So kindly get your check up done and undergo either root canal treatment or extractions, whatever advised. The dentist when checks would be able to tell you what actually has to be done because it is impossible to just predict of what has happened. So kindly visit a dentist and get your thorough check up. Also as there is severe pain, please take one tablet ketorol DT which is a painkiller so that you may be temporarily relieved from pain.