It probably would be a good idea to see a Rheumy anyway. It's possible he/she might know more than your current doc and know more about different medications that could be used to try to help you. Also, they would know exactly what different tests to run. I don't know if you've had all sorts of blood work done. Did your GP run blood tests? Did that doc check you for all the tenderpoints and such? It just sounds to me like that doc isn't interested too much in trying to investigate things for you. So perhaps a Rheum might investigate more, or listen to you more. If you do see a Rheum, get copies of any tests you have had done, and make a list of all your symtoms. Also, try to think if your symptoms come on in relation to anything. Give good descriptions of your symptoms. Really describe what your pain feels like. If your pain is really bad, make sure to get that across. Tell them how the pain is affecting things in your life. Some descriptive pain words could be: achy, deep achiness, sharp, shooting, crampy, bruise-like, throbbing, tingling, burning, etc. If you get worse while walking or going up & down steps, tell them that. Tell them if your legs feel heavy. Use good descriptions for your pain and try to be as specific as possible in pointing where you feel pain.
For example, (though this has nothing to do with Fibro, it's an example of how i've described some sciatic pain i've had): I had sciatica that was so severe, my left foot was completely numb, no feeling in it, and I could not feel where the floor was. The nerve pain felt as if someone cut me open along the entire sciatic nerve path and felt like rubbing alcohol was being poured into the wound 24-7; The nerve pain in my ankle felt like someone was using an electric nail gun and shooting large nails into the side of my ankle. I've had pain inside my spine which felt like I was being compressed. My body felt as if I needed to hang upside down and be pulled apart to relieve my pain. I have Lupus and also been told I have Fibro. But i've had flares of severe fatigue and my legs felt as if they were cement blocks. I had such pain just going up one or two steps. Now I get really bad pain (and nerve pains) around my hips & down my legs. My entire pelvic girdle and sacroiliac areas hurts. When I stand or walk, it feels like a huge cement block or boulder is sitting on top of my pelvis. It's almost like a crushing compressive feeling.
But anyway, I hope this helps somewhat for you to try to think of good descriptions for your pain. And when you see a doctor and they ask how you're doing....don't say you're Okay! LOL Tell them you are in pain, you don't know why, and you want a doctor that will help you investigate and help try to treat it.