Brother! The same thing happened to me after lockdown in my area. I started sitting long hours due to work and stopped physical activities like walking-running. After 6 months, I developed this gastritis. The docs gave me the same tablets as you and still no cure. But, I started doing daily exercises for 1 hour and atleast 5kms of walk or run. Drank warm water after getting up from bed at 7 am. Avoided citrus diet and also reduced diet a bit since my belly fat had increased. After 4 months of pain and strict diet, I am fit as a horse now. It takes patience and time. Best of luck.