Your symptoms suggest that you may be suffering from LPR. It causes discomfort , pain, irritation, cough,lump sensation etc. in the throat. The symptoms particularly occur after meals and when lying down. It is relieved after drinking water or antacids.
Next Steps
Consult an experienced ENT doctor in you city and get FOL done to confirm the diagnosis. The condition should be treated with PPI and anti-reflux medicines for a long period along with life style modification.
Health Tips
Avoid smoking, alcohol and speicy food. At night do not go to sleep at least 2 to 3 hours after dinner.