This is Dr. David
gastritis is most commonly caused by excessive stomach acid, which can come up at night time and burn the back of your throat at night time when you sleep
this can cause pain when sneezing and yawning in your throat.
if you sleep on your left side, stomach acid can sit there on your throat on the left side all night
you may need stronger stomach acid blockers to decrease stomach acid
you may need to change your diet to avoid foods which worsen stomach acid like fatty foods, spicy foods, tomato sauces, alcohol, beer, fired foods, large meals.
you should be checked for hiatal hernia which can cause worse stomach acid reflux as well.
let me know if you have questions.