Thanks for writing your query.
It will be helpful if you mention more about your stools like consistency, frequency,etc.
After reading your post, it seems that you might be having gastritis
You can take an antacid like Omeprazole
40 mg once daily before meals, a digestive enzyme
preparation containing pepsin and fungal diastase after meals.
If nausea or vomiting is present you can add Domperidone
30 mg along with the antacid.
You should eat light meals prepared under hygienic conditions with less spice and oil.
More can be planned after knowing the consistency of your stool.
I hope this is helpful to you.