I hear you OP.
I'm not in as difficult a position as yourself but I do absolutely empathise.
I suffer from eczema and thankfully I manage to keep it under control about 60% of the time.
Similar to arthritis, there's a tendency for people to "know" someone with a relatively mild version of the condition and simply don't understand that some of us are living with these conditions that are in a different league.
On a day to day basis I have to look after my skin very carefully to prevent a flare up and that impacts a whole lot of choices that most people wouldn't understand (from what environments I can be in, what clothes I can wear, how I bathe, how often I have to moisturise and being in a place to do so, what make up I can use etc).
That's a PITA but frankly tolerable.
However when I get a flare up I can be in agony with weeping, cracked even infected skin that's on occasions has led to being hospitalised.
I've been in the toilets at work in tears from the pain of gently moving arms and legs that are cracked/weeping and bandaged (and hidden under thick tights/work clothes that do a good job of hiding it but actually make it worse).
I've removed work shirts (I wear under a blazer/jacket) that are so bloody after a day in the office they look like I've been flogged
- and that's just the scabs, opening and bleeding from normal movement.
Worse it itches and hurts so much it's constantly on my mind - it's like living with half your brain engaged elsewhere and more so when you're also sleep deprived from the same condition.
Work colleges haven't a clue and tbh I don't want them to.
They know I have eczema but I think they'd be horrified if they ever saw my skin in the midst of a flare up.
I've had much planned holidays ruined/cancelled, major life events compromised and it's so damn annoying.
So I get you OP and rant away if it helps because I do have a notion of how shit it is even if I'm lucky enough to we mostly well 60% of the time. 