We need to address many issues for you. One is gastritis
, second is decreased immunity due to medications, third is dealing with ongoing conditions. Osteoarthritis
needs pain-killers or NSAIDs that can cause gastritis. Steroids
, alcohol and stress can also cause acidity. Thus I will suggest that you take antacid medicines appropriately and avoid medicines and food that can cause gastritis. The antacid medicines can include antacids, H2 blockers, Proton pump
analogues, etc. Check with your physician about which medicine will suit you. Take high fiber food. Take hygienic diet and clean drinking water to avoid unnecessary stomach infections.