I can tick most of the boxes on this, although I've never been diagnosed.
A lot of the symptomology fits well with Learned Helplessness
and Attachment Theory, with an imprinted internal working model that persists and reinforces itself. In my case this was the near-simultanous death of my mother and alloparents as a child, leading to pretty severe withdrawal until my late teens, and moderated somewhat since, although I still have my problems. Won't go too far into the personal side, you get the picture I hope. Withdrawal seemed
to work for a long time, so there is a lot of neurological and behavioural 'habit' in place.
I don't know about support resources; I've tried using script rewriting, NLP etc, but found these didn't cut it when an 'attack' was on me. One trick I did find useful is what Buddhism calls mettabhavana
, which means cultivation of compassion. Think of a secure, ideal-ish relationship, if you have one, and just feel that, and try and feel loving/loved. Next do the same with someone you have no affect one way or the other for.
I found this helpful. I suspect it helps entrain your brain to feeling trust and loved, which is no bad thing, even if you don't buy the religion behind it. You can experience trust and anxiety states in a controlled manner...
The object (I think) is to prove it wrong repeatedly enough that the lesson sticks; ultimately this can only be done by the risk of trying to connect.
It's worth the risk.
Yours in sympathy,