You need to follow a healthy diet. Avoid spicy foods, oily foods, outside junk foods, tea, coffee, sweets, sugars as much as possible. Have 4-5 short meals per day, instead of three big meals. Eat foods rich in fibres like green leafy vegetables, raw fruits. Also drink plenty of water in between meals and little water during meals. You can take pantoprazole 40mg once in the morning half hour before your breakfast for one week. Sometimes stress can also trigger gastritis. So try relaxation methods like yoga or meditation. Also do not starve for too long. If this doesn't give you relief then consult a general physician or surgeon for further evaluation.