Hi, I have a mystery disease that has stumped 7 doctors so far. I have no overlap with your problems medically, but the fear of your last sentence is a very valid and real concern. The person that helped me the most was actually a nurse practitioner (in the us, not sure if thats a thing other places). Id recommend seeking treatment for the symptoms at first, and the once you find a dr that actually helps THEN i would ask them what next steps they recommend.
Also find a way to tell someone your medical history in under two-five minutes, doctors all have atention span issues. Heres mine if it helps
“I stopped feeling hunger when i was 17, waited on that for about 10 years as it didnt seem like a big deal, now Im constantly nauseous and in pain” you can also add on what youve tried, but that should also show up on your medical records from past drs.