I found this today, which is really helpful explaining how this happens:
https://www.ptsdforum.org/c/wiki/belief-systems/
Sadly, I see a lot of myself in here. Resigning to the possibility that this is for real. On the one hand, ugh. On the other hand, at least that means we have a way of categorizing what I'm feeling that has a recommended line of treatment. I'm sick of feeling like crap.