Hello Coo....I just wanted you to know I have been where you are, and understand how frustrating it is. I had fibro for 10 plus years when the new and different symptoms began. I've always said having the fibro diagnosis did nothing but hinder sorting out the connective tissue/AI problems.
I'm on my third rheumatologist. My ANA has been positive for 3 yrs - the highest was 1:1280. I've been on Plaquenil for 2yrs. My official diagnosis is UCTD, but I've recently had a positive RA factor, so things may be coming into focus, who knows? I take Plaquenil, which has helped, but I still deal with serious fatigue. Sometimes it's hard to know whether the fibro has got you down, the lupus/RA/whatever, or both!
Getting treatment for your symptoms is more important than the diagnosis. A good rheumatologist who is familiar with Lupus is what you need, though they are not always easy to find. Get copies of all your test results and keep track of your symptoms. Other tests should include ESR and CRP - which indicate inflammation in the body. Fibro shouldn't cause inflammation. There are others I can't think of right now. Unfortunately, normal readings don't rule out much of anything, either, as you can be sero-negative and still suffer from autoimmune disorders. Using different labs can complicate matters further. Personally, a rheumatologist who attributed everything to fibro after you've been dealing with it for 20 years, would be reason enough to look for another doctor - at least in my opinion.
It's not an easy road, and I wish you weren't on it, but this forum is full of good folks who are supportive and informative. You know your body better than anyone - hang in there!