You may be suffering from ulcer.
Avoid outside foods. Avoid oily and spicy foods altogether, avoid smoking and drinking alcohol.
Avoid tea, coffee and other carbonated beverages.
Have meals at regular intervals and at fixed times.
Divide your meals into smaller portions of 5.
Drink lots if water.
Don't sleep immediately after foods. Let there be atleast 2 hours gap between food and sleep.
Take a tablet rantac 300 mg half an hour before food for 5 days once a day.
If it still persists, consult a general surgeon for further help.
You may need a endoscopy and ultrasound along with other blood investigations.
Dr. Anil Kumar Jain