Thanks for using Healthcaremagic,
After going through your history, you have breathing difficulty but physical examination is normal including X ray
You should get Lung function test to know if there is any Asthma
issue, if everything is fine then as treatment you took did help you so there may be Gastro Esophageal Reflux disorder (GERD).
You should get test for H Pylori and Endoscopy
to confirm the cause and Diagnosis treatment would depend on cause.
If you have any food allergy
it may also be tested and treated accordingly.
Hope this helps.
Dr.Akhilesh Dubey M.D