Hi., I can understand your concern.
It can be due to Gastritis.
You need to do warm ups in between your job. Need to change sitting positions.
Plan for a quick walk after every meal
Chew your food well
Next Steps
for now you can take
tab pan 40 twice a day before food for 5 days
tab gelusil 3 times a day after food for 5 days
syp sucrafil o twice a day before food for 5 days
Health Tips
avoid processed foods.
avoid drinking more water right after food