@leslie10152 - I'd go along with the others in asking you to disconnect yourself from the view that you're indispensable. Nobody is. If you were abducted by aliens (OK, less likely, but just trying to convey the idea of disappearing unexpectedly), would the business open next day? Would profits plummet? Would the workplace world stop spinning, or would it be a bit uncomfortable until responsibilities could be reshuffled or re-attributed? What happens when you go on holiday?
The bottom line is if you run yourself into the ground, the only person who will suffer is yourself, and that's not even considering any damage you could be dicing with from those widely swinging blood levels.
You are in a situation where, today, you can manage your absence a bit. By that I mean, you can make a conscious decision to look after yourself and maybe even write a list of things that would have to be delegated, with suggestions from your most capable members of staff, or list the things you have coming up, that require management consideration.
If you continue as you are, you could easily find yourself in a situation where you leave your employers in more of a jam, by doing that disappearing off the workplace scene, unannounced.
Some years ago, after my Mother passed away, I was in a new job (first day back from very modest compassionate leave had me starting a new job, in the same company, but in a different area, with different people, and I just felt they would think badly if I extended my leave. The job involved a whole load of travel to somewhat anti-social places and it just ground me down, until I ended up having a couple of months off.
I had ground myself down to a place where my initial thoughts of, "I could do with a week to draw my thoughts into order", just wouldn't cut it. Don't do the same as me.
Nobody likes to let anyone down, but right now, you are letting yourself down, with the knock-on effect of others. I'm sure you're not performing at your best (even just taking your blood numbers into consideration).
I would urge you to take some time off, but proper time. I doubt the odd day here and there will cut it.
With my old employer having a day a week off, or any other regularity, would have been flagged and HR/Occupational Health would have been all over it, like a rash. Whilst that gets matters out in the open, it might not help your anxiety levels.
Leslie, only you can decide how to handle this, but I know where my vote would be. I'm sure it's not easy for you.