Thanks for writing your query.
After reading your post, it seems that you are having gastritis
and Gastro Esophageal Reflux Disease(GERD).
You should follow some precautions like :-
1. Avoid spicy and oily foods.
2. Do not remain empty stomach for long durations.
3. Avoid smoking and alcohol, if any.
4. Avoid emotional or mental stress.
5. Drink lots of water daily.
You should get your clinically examined and investigated by an ENT specialist
and a dentist
for foul smell from your mouth.
You can take an antacid like Omeprazole
40 mg once a day before meals.Dicyclomine
can be taken after meals for spasmodic pain in abdomen.
You should eat light meals prepared under hygienic conditions.
Also maintain your hydration.
I hope this is helpful to you.