Lifestyle and food habit changes. Is the endoscopy report saying RUT positive or not. if RUT is positive you need to use antibiotics as per dr advice. avoid eating food stored in fridge i.e. yesterday food. eat freshly prepared food only. avoid outside food completely,  no tea , no coffee. stress from family or work should be handled properly.stress also causes gastritis. it should not take more than 3 to 4 months to heal. as you are saying weight loss, try to get endoscopy again.