Sorry you're having such a rubbish time. I have severe anxiety (panic disorder) and OCD - which led to a breakdown at some point in my 30s, hospitalisation, etc. And yeah, I hear what you say about feeling as if a switch has been flicked. It's weird. I also had bad PMS, so don't know whether that meant I was sensitive to hormones or what.
Anyway, is there any chance you could get an appointment with a mental health nurse at your surgery? Might they be able to prescribe you some insta-acting rescue meds? Proper rattling with anxiety is exhausting and seems to get right inside my head until I'm spiralling. It can be a bit difficult to get out of that phase without the help of medication (for me). Also, you know, because I've been so poorly in the past, it's frightening to think I might end up back there. As it goes, I haven't, and I think that's because I've been in therapy for 5+ years now. A recent diagnosis of autism has also helped me to understand how I end up in / can manage OCD loops better.
I think the point I'm trying to make is that the fact you ended up in A&E seems to suggest a mental health medical emergency. Could be all sorts of causes for this, including low E, but also taking steps to knock it on the head ASAP could be a route you want to go down just to buy yourself some breathing space.