@SarahSon - You are fortunate your gastritis symptoms went away with some short term medication.
I have lupus, which is an autoimmune disease, and this adversely affects so many other areas of the body.
Because of this, I have developed what the doctors call autoimmune gastritis. Anytime someone has an autoimmune disease it is very hard to treat, because your own immune system is attacking itself.
My gastritis treatment involves taking some medication, but I think this is something I will have to remain on for the long term.