Gastritis Diagnosis

Hey guys, Ive (22F) posting a lot lately, mainly because Ive wanted to try OMAD for quite some time and because I was trying to see if anyone else has done it for reasons pretty unrelated to weight loss. Sorry if this is TMI but I just today got diagnosed with chronic gastritis. At 22!! Which is pretty crazy to me honestly. Ive had stomach issues my whole life, but I can't believe I finally got some sort of diagnosis. Anyway, so I was wondering if intermittent fasting or OMAD has helped anyone with gastritis or anything related? Do you follow a low FODMAP diet? What are you eating? When? Thank you!