Jennileerose,
I don’t have fibro, but my sister did, and she had a lot of pain. I suggest a very slow, gentle practice, such as some hatha yoga. I apologize, I don’t know enough about all the “styles” of yoga practice, but for your condition, you need one that focuses on gentle stretches and breathing above all, as that will bring circulation and oxygen to the fascia, which is what is affected with fibromyalgia. I think others reading your post may be missing that important fact, that fibro affects the fascia and the joints as well, so you need something gentle that really focuses more on getting oxygen and circulation to the fascia.
I agree wholeheartedly with Gordon, though, go to some yoga classes but ask to speak to the instructor ahead of time so you have time to discuss your condition and some modifications. you might even just call the yoga studio, tell them your condition, and ask them what they recommend. Disclosure is most helpful above all, and you will get the help you need in that way.
I also agree with Gordon that you need more than just the focus on the physical. Since fibro affects EVERY part of you, including the spiritual, you would benefit from a practice that encourages more than just the physical side of “doing yoga”.
And don’t forget, the breathing is most important!