Hm. IME, mostly just trauma/frozen emotionality. And being surrounded by noise and assholes.
You get that out of the way, and the whole world opens up.
<3 sorry for misunderstanding. Yeah pain receptors are a pain. The body sure likes producing pain.
Alchemical transformation is a bit above my pay grade still.
It seems like the base pain sensations themselves can be befriended, but no idea how physiological aspects of it work.