Brief Answer:
Might be deep decay or fracture, x ray, medication, treatment..

Detailed Answer:
Hi..
Welcome to HEALTHCARE MAGIC..

I have gone through your query and can understand your concern..

As per your complain pain in tooth can occur due to causes like deep decay in tooth that can cause inflammation and irritation of nerve leading to severe pain, tooth abscess formation due to decay reaching below the root tips of tooth..
Fracture or crack in tooth can also be a cause for pain..

So my suggestion to you is that you should consult a Dentist and get an x ray of your painful tooth done..
It will help in ruling out the exact cause of pain and will be treated accordingly..
Treatments like Root canal treatment can be advised if tooth is in a condition to be saved..
In case if the tooth is grossly decayed or have vertical fractures then extraction [removal of tooth]is advisable..

As of now you can take painkillers like Ibuprofen, Diclofenac if there is moderate pain..
If pain is severe then higher pain relievers like Tramadol, Ketorolac can be taken..
Do cool compresses over the cheek..
Take a soft diet and avoid chewing from painful side..
You can also cool your food to room temperature before taking to prevent sudden nerve irritation that can increase severity of pain..

Hope this helps..

Regards.

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