I, too, have fibromyalgia. I tried the no yeast/sugar/white flour diet 20 years ago - no results. Also cut out dairy, with no results. But that was me.
What finally helped me with fibromyalgia - and I was miserable with pain from it, on the brink of having to quit my job, quite literally doing nothing but laying around the house on weekends - was a cheap, old anti-depressant, Elavil. Within one week I went from hardly able to move or sleep from pain to almost my old self. I tell people that my bad days after starting on the Elavil are like my GOOD days were before I started it. It is the one drug I will never give up! It gave me back my life. However, I know others who have tried it without success.
Acidopholus is to promote the growth of "good" bacteria in your system. The good bacteria prevent overgrowth of "bad" bacteria, and help to bring and keep yeast growth in your system under control.
I'm curious - What tests did your DR do to detect the yeast overgrowth in your system?
It's tough to have food allergies, especially if you have really bad reactions.
I really hope this diet helps you. I know just how bad fibromyalgia can be.