I have Fibro, diagnosed last Autumn after two years of being unwell. I think they like to rule out everything else it could possibly be before diagnosing it. There is a huge list of symptoms - I wish I could find it to show you. But a lot of them ring true for me. Generally I think they say it's defined as constant pain in al four quadrants of your body for over three months. The symptoms I have are:
Feeling stiffness in arms/legs when you've been sitting or lying for a while. Which goes when you've moved around a bit.
Extreme, burning like pain in muscles - usually arms or legs. Sometimes pins and needles and swollen hands. Chest/rib pain.
Inability to sleep. I'm not sure if this is one - I think it's "sleep disturbance". But I'm regularly still awake at 3am, unable to sleep. They think you don't reach the third phase of sleep or something which leaves you still unrested when you wake up.
Dry eyes - mine randomly stream bucket loads - when I'm not crying.
Sometimes I can't bear people touching me because it literally hurts. It's like an oversensitivity. If I bang my foot or something - it hurts much more than it should.
The fatigue is quite different to that I had when I had chronic fatigue a few decades ago. With the CF I could sleep for 15 hours at a time and wake up feeling tired. With this - it's more physical. I can be walking home and hit a barrier where I really can't put one foot in front of the other. It's like wading through treacle. My hips and ribs feel like they can't hold the weight of my body. If I've overdone it in terms of physical activity my body goes into this juddering phase. You can't see it but it feels like my whole body is shaking inside.
Bladder irritability.
Brain fog - I used to be a very accurate person administratively. Now I make mistakes frequently. Things like paying money onto the wrong credit card. Not understanding for ages why a password doesn't work - later find out it's the password for something completely different.
It's hard to say because I think different people have different symptoms and there are loads of them. But the rheumatologist will do a series of tests to rule out things that can be tested for first. If your GP hasn't done blood tests, I would ask them to. Because as people say, some deficiencies can cause some awful symptoms.
Fibro is not a particularly good diagnosis to get. There isn't really anything they can do for you - except painkillers and pain clinic. It's a bit of a life sentence. You have to adjust your life to cope. I've not worked since the new year because I can't. I'm trying all sorts to get to a point where I could work part time. Gluten free, regular swimming, relaxation, zero stress.
They don't really know what causes it. Things suggested are sleep problems, having had chronic fatigue in the past, gluten sensitivity (not necessarily Coeliac) and more recently they seem to be making links with having the TVT operation (which I've had) - amongst many other ideas.
I hope you find an answer soon. I think the limbo period where they're trying to find out what's wrong with you is the worst actually. But many of these things take an age to diagnose.