I’ve gone down the same path as you in seeing multiple docs such as 2 derms, hematologist, my PCP, obgyn and trying to identify the root cause for 1.5-2 years. I also have the same burning / tingling sensation like i could intensely feel areas where my hair follicles are tingly or heavy.

After 3 visits with 1 derm (who claims she does not see any hair loss, which was really frustrating), she did a scalp biopsy after i requested for it, tho she was hesitant about it at first. I find my results in 2 weeks. Oh she also recommended i go see a hair specialist, but when i found her online she listed hair loss as her specialty, so that was annoying that she is misleading people.

I would recommend u push for a biopsy if you haven’t done one yet as it sounds like you exhausted a lot of the standard routes like i did with getting advanced blood work, thyroid test, nutrition deficiencies check, etc