Stomach infection or gastric problem?

It is likely to be gastiritis. I would advise you to have an antacid and deworming medicine(if you haven't had in 6 months). These following steps may help: - Don't skip meals, you may not feel like eating but in such conditions you should have the reduced amount in frequent intervals(i.e. 3 square meals broken down to 5 or 6 as you can tolerate) and slowly increase as you get better. - Reduce/ Avoid spicy,fried, fatty, junk and oily food - Avoid/ Limit drinking coffee, tea and carbonated drinks to once a day - Exercise regularly - Increase daily intake of water to 3liters - Avoid/Stop smoking and drinking - Reduce stress through methods such as yoga/meditation. If the condition persists or worsens visit the ER at the earliest.