Whats the worst thing to eat too affect gastritis?

No spicy,acidic food. You should avoid spicy food, and acidic foods like tomato sauces and orange juice. Also you should try to eat small frequent meals. Pain is worse with an empty stomach.
Chicken vindaloo? Acute gastritis-inflammation of stomach lining due to meds, alcohol, even acute h. Pylori infection. Stick with bland diet, no alcohol, minimal caffeine, no hot, .Spicy food; may tolerate cooked fruits and veggies better than raw. Chronic gastritis due to h. Pylori, or autoimmune? Maybe the above reccs as well. See doc to get checked and treated. May tolerate more foods once on appropriate rx.