For me personally, I've never experienced the gastro symptoms you describe with my Fibro... but then again, Fibro/CFS can rear it's ugly head in so many different ways.
I would definitely seek the advice of a Gastroenterologist.... just to rule out any other conditions that could be worsening your condition.
I agree with kris_tin29, you should probably seek out the advice of a Gastroenterologist. I am not well versed in disorders of the stomach, but there are a number of different ones. You case does sound a lot like one that a friend of mine had who I used to work with. He had a severe case of Gerd and lost an incredible amount of weight, but again perhaps it's something else. Check into the GI doctor and let us know how you do. Good luck.
-Dusty
Regarding your stomach issues: Do you feel full even when you haven't eaten or have eaten very little or do you ever wake up feeling full. is your bloating severe? I am asking because I have a condition called Gastroparesis which literally means "paralyzed stomach". It is when your stomach muscles do not contract properly or at all resulting in the food just sitting in your stomach. the symptoms are vomitting undigested food, fullness feeling, weight loss without trying, etc. My symptoms were nausea, stomach pain, rarely i vomitted, fullness feeling all the time and this huge bloated stomach. The condition can be associated with other autoimmune and neurological disorders. Also, people with Diabetes sometimes also have this. The mayo clinic website has good info on it. My Doctor actually printed the info he gave me directly from their website.
It may be worth looking into, especially since you have other symptoms and it can be related to other conditions. You may want to ask for a referal to a gastroenterologist.
As far as the other symptoms, I have yet to be dx with fibromyalgia, so I'm probably not the best person to answer your question. It does sound as though you need some tests run to rule out some other causes if you haven't already done so.
Good luck to you,