Being 22 and living a "clean" sorta life doesn't matter...children get AIH. It has nothing to do with lifestyle, weight or age. I would press the issue of AIH. It is common to have both AIH and celiac and since you have celiac....why isn't it possible to have AIH when they travel together a lot? Have they not sorted out your "connective tissue/Sjogren's"? I had been seeing a rheumatologist for 3 yrs prior to my AIH diagnosis. I had elevated ANA and joint pain so they thought I had some kind of connective tissue issue but no other antibodies ever showed up. Then I got sick; vomitting, extreme shivers, iced tea colored urine, became jaundiced...after 2 weeks of every other day blood work with checking every possible virus...my labs kept getting worse so my hepatologist was 98% sure it was AIH and I had a biopsy to confirm...now I'm medicated but perfectly fine. So maybe it isn't a connective tissue thing at all....maybe it's AIH. I'm not pushing you to have it as no one wants it
but if it is that, you need to make sure your liver isn't being severely attacked and that you control the disease. It is a potentially fatal disease without treatment.
Luckily your labs aren't super high. They generally only get really nervous when they are over 100. Mine were AST 748, ALT 848 and by the time I was hospitalized for the biopsy, my bilirubin went up to 23.3...and I was no longer able to clot. However, everyone responds differently. You may still be causing enough damage to your liver so the sooner you get a grip on it, the better. You want to avoid cirrhosis at all costs...that can't regenerate but fibrosis and lesser damage can.
I would ask your new GP for a referral to a hepatologist and if they won't let you see a hepatologist then ask to see a GI doc.