Gastritis Support Group
Gastritis is a medical term for inflammation of the lining of the stomach. It means that white blood cells move into the wall of the stomach as a response to some type of injury. Gastritis has many underlying causes, from infection with the bacterium H. pylori, bile reflux, or excessive consumption of alcohol or certain foods or drugs like aspirin.

I'm so sorry you're going through this! You're such a trooper going through this for 12 years. I've had gastritis/reflux for 4 months and it's driving me crazy!
I hope the meds work for you and they can figure out what's going on. It does sound like an ulcer. I'm seeing a nutritionist in Scotland where I'm from who thinks our issues come from low stomach acid. This started for me in full force after a course of antibiotics so the nutritionist (who is also a qualified gastro nurse) thinks my gut bacteria are to blame for my symptoms.
Of course it's all anxiety inducing- which make the symptoms worse!
Usually from the food remaining and then causes risk of repeat infections or ulcers
But also a possibility of some occassional reflux for you redstar which would only be caused by a loose sphincter if it was regular pain
Probably the gastritis is more long term for you and the pain not so often?
Ive had a few gastric polyps removed
My first endoscopy was misdiagnosed-apparently they 1st thought it was a loose sphincter
I have read that long term use of PPI medications can lead to problems with bone density. I'm beginning to lose faith in them.