yeah, this sounds a lot like what I've been going through.
with the worrying, is it like catastrophising? are you imagining conversations, scenarios, that kind of thing? with me, I would get stuck with something looping round, or just some terrible version of events playing out. might not be the exact same thing, idk.
this has been accompanied by most of those physiological symptoms you mentioned, and the attention span thing.
when you talking about feeling yourself acting erratically but it being out of your control, that sounds very familiar. it's all impulse stuff, like that part of you is haywire whilst the deeper cognitive side has fallen into disrepair?
I can't say I've completely overcome all of this, but I've been coping a bit better. I did have to quit my job, though.
I feel like I need to pick up this book again:
(I know, reading is one of the things it's hard to do)
it helped change my perspective with regards to mindfulness, being aware of when my impulsive side is about to take over (in a bad way - obviously it's important for lots of good/important functions), when my cognitive side is tired, how to stay balanced.
I did take Venlafaxine for a bit, which helped with the worst symptoms of the stress/anxiety - heart pains, feeling like I had the flu, headaches, etc. then I came off it cold turkey. not recommending that, I just felt like I had to. kind of rebooted my brain a bit.
I don't know, to be honest dude, I'm just throwing my experiences out there. I recommend you see your GP and try and get some old fashioned therapy or CBT, because everyone is different. good first step seeking advice here, though.