Barbara, I also struggle with fibro. I've taken up photography since I was diagnosed & find that, while I can't do a lot of things, photography is one that I can. For whatever reason I can carry my camera & bag for hours with little or no pain. That is really surprising because most days standing up is a challenge. I use a Vanguard CF monopod and really like it. If my camera's not on it I use it as a walking stick. I've given it more abuse than I think it was built for & is still serving me well. I'm not going to suggest that you should drop what you're looking at & get the Vanguard but I do want to point out that the inexpensive can, at times, do just as good as the more costly one. Since I am not able to work full time I have to watch what I spend on my camera gear. So I look for the most value I can get for my $$ and, at least for my tripod & monopod needs, Vanguard is my choice.
I hope you can find a monopod that fits your needs and that your fibro will let you get on with your life with as little pain as possible.