1swede, I can completely relate to what you are saying.
In jobs I have had, I was always the one who would pick up the slack, even things that were not my job to do, because.....well....it had to get done, and Somebody had to do it and so I would do it.
the thing is that of course I learned that pretty soon everyone noticed that, and while the boss might appreciate it, the other people I worked for simply started taking advantage of it. Knowing I would do it, they shirked their own duties and left them to me.
You would think that I would have stopped doing it, but I am either dumb or else just have too ridiculously strong of a work ethic, because I couldn't stand to just walk away and leave something undone that needed to be done. So the situation always just got worse.
Even now, it is very hard for me to say no. I have my own business, and should have cut back more on how many days a week I work, but when someone calls me and says they really need me, I just never seem to be able to say no.
I know that I have a choice: either I cut back, or stop working completely, or else one of these days I will hurt myself or else the fibro will get so bad that I won't be able to work at all. Or do anything else I want to do!
I should stop working so much while I can still do some things I want to do and I don't know why I don't.
I think it is possible that many, although I am sure not all, people with fibro are those who were hard workers and/or accomplished in their lives. But I don't think there is any reason, as such, that these things happen. they just simply do. Good things happen to good and bad people, and so the bad things. that is just life, no reason for it, just nature taking its course.