PBP,
Definitely push to see a specialist. If there isn't a hepatologist then, at minimum, see a GI doc. It is very possible that it started as drug-induced hepatits but, as I've said, if you are predisposed to autoimmune disease, it can become AIH. A biopsy will help with a definitive diagnosis but there are antibody tests they can do as well. There is also PBC (primary biliary cirrhosis) and PSC (primary sclerosing cholangitis) to look into. Don't discount other viruses or infections as Hugh mentioned Lyme's disease. It sounds like you have a proactive GP so that's awesome!
I hope Wednesday goes well!