Are you on a wheat free diet? I don't (as far as I know!) have fibromyalgia, but had increasing pain over the past 15 years or so (random, gut and joint) which got a lot better, but didn't go away when I went on a low carb diet (which of course included sharply reducing the amount of wheat I was eating).
This year, I have cut wheat out totally, and the headaches, gut pain, random pains, joint pains have all stopped.
Do you think that would be worth a try (you may feel quite unwell for about 3 days, as you withdraw from the wheat, I warn you!).
With a low carb diet, you won't get cravings... unless you are eating too much carb, craving it means your blood sugar is spiking too much (making you hungry when it drops again).
Eat biggish meals with plenty of fat (yes really!), and protein and no carbs except what is in your (non starchy) veg (eat lots!), a few berry fruits and nuts, you won't feel the need to snack often, and a hand full of tree nuts or fresh coconut or a couple of squares of dark (80% or more) chocolate will do.
You WILL lose weight on this, and it won't feel like a diet, IMVHO and E.
There are low carb/paleo threads on here with lots of info.
This free blog has lots of info, ideas and a lot of science, if you want to look more deeply into how and why this way of eating works for a lot of people.
www.dietdoctor.com/
I think I may have seen some stuff about fibro on there somewhere.