I'm sorry you're dealing with so much. Endo alone is terrible, much less everything else.
Do you know what kind of herpes blood tests you had? Can you get copies of those results? It's important to know if they were IgG or IgM.
I had endo for a really, really long time - from the time I was 12 to when I got a hysterectomy at 33. Women with endo get loads of different symptoms, but it doesn't cause rashes (as you know). A couple of years after my hysterectomy, I got hsv2, and I've had it for 15+ years. Herpes symptoms can vary, but it wouldn't cause all that you're experiencing.
Other than the initial cultures that came back negative, have you had any other cultures or any biopsies?
And what is a stress rash from guilt? Do you feel guilt from something? You don't have to share what, but is that even a thing?
I'd wonder if you're allergic to something - laundry detergent, body wash or soap, some fabric - you mention scrubs, and I wonder what material those are. Are those professionally laundered or do you wash your own? Do you notice any improvement on your days off or even better on vacation?
I'd also wonder if your pain is coming from a pinched nerve or disc injury. You could also have endo on a nerve that is causing problems.
I know how frustrating it is to have pain and not know the cause. I hope we can help figure this out for you.