Allergy and gastritis. Cure completely?

Hi I am SACHIN SAXENA, male 33 years Recently I had uneasiness , vomit and pain in upper abdomen between chest area and pain with breathlessness also goes to back which makes it very stiff. I went emergency , they told me this is gastritis . Also I didn't feel hunger as earlier I had due to which my weight loses 3 kgs. Now I consulted a doctor and taking treatment medicine as "veloz 20 & normaxin tablets for 10 days. It's 3 days now my pain improved much and also I am taking very light diet .But at nights i feel that some burp is stuck with slight breathlessness and when I sip water , reverse flow back with yellowish liquid or sometime not. After which I feel stomach full feeling even I hadn't anything.  Is this gastritis or something serious and if gastritis how long will it take to cure completely ? My past medical history is not good. I have nasal septum deviation Allergy Tonsilitis Allergic rhinitis And this one gastritis new on list. I am really frustrated .