Dont worry just be relax, because too much worry may also cause gastritis
Reduce on your intake of hot, citrus and spicy food.
Have food at regular timings.
Drink 1glass of luke warm milk at night.
Drink 3lts of water daily.
take tab amla 2tab twice after food.
tab yastimadhu 2tab twice before food.
Take all the above for 1month and let me know how you are feeling after that.