As I slowly process my gender feelings now I'm on HRT I am realising just how insidious it has all been:
in my 30s I "decided" to suppress ALL the crap I was dealing with. Not least because prior to that I'd been pretty unstable. A. points out it would have been likely I'd have gotten a BPD diagnosis in my late 20s!!
This lead to years of depersonalisation
prior to that it had been all over the place & far more noticeable but I just had no concept of what to do about it