Suspect histamine intolerance…so now what?

I have a rant. 4 years ago I develop GI issues, anxiety, and weight gain. Doctor says perimenopause sends me to a GI doc. GI doc says colonoscopy to help ease my anxiety and once all clear is declared they have me start anxiety meds and I make lifestyle changes to manage IBS. Last year I start having heart palpitations, do all the testing and decide it’s perimenopause. Ok. 10 months ago IBS is just not controlled so primary says start a med for bile acid. Ok. That creates gastritis in December. Ok. Endoscopy, all
Clear so start diet and Pepcid. Lose 30 lbs. great. Discover Pepcid is magic for my IBS. 4 months ago have a BPPV episode. Resolved. 3 months ago develop neck pain, dizziness, headaches, so primary refers to PT and neurologist for vestibular migraines. Cool. PT double checks for BPPV and clear, neck pain resolving with therapy. Neurologist thinks neck tension but orders MRIs and b12 labs. Awesome. MRI comes back clear but b12 is rock bottom. Fine. Refers me to a hematologist since I have a benign blood disorder as well. Ooohh kaaay. Start taking b12 low dose and experience ALL the things as my body is shocked by b12 in it and primary confirms normal. What do I think? I think I have histamine intolerance and it’s literally fucking my system. Great so now what? Who handles that? Which of my dam specialists are going to manage that cause it sure isn’t my gynecologist. Who the hell do I talk to about this? I get in lucky I have appts and can bring it up but at what point does someone notice that all of this is peri and my system is jacked up?! Everyone has been pretty good but I’m tired and feel like jittery shit from the b12. You are my people so figured you would get it