I do have some cramping and twitching, but not to the degree you are describing. I wonder if you are low on something. I find the cramping is reduced when I take potassium. Hmmm.....Sorry I couldn't help. :-(
I think fibro has so many tentacles that it's possible. Give others a chance to chime in. I have found so much out about things that my body is doing through the others on this forum, that my issues are shared. Some have many issues, while others are mainly just overall pain. Unfortunately, I'm on the many issues side... :-(
You mention that you hope the diagnosis of fibro is what sticks and not something else. Just remember, knowledge is power. If it isn't fibro and you get a different diagnosis, learn about it so it isn't scary. We can deal with the known so much better than the unknown.
You are doing the right thing getting into specialists. Keep a positive outlook and please keep me posted on how you are doing......
Have you tried magnesium to settle the twitching? It works well for calming mind and body. Do hot showers/baths work for you at all-or a heating pad?
Nothing much is "typical" of FM, everyone is so different. I don't think it is time to panic, there are things you can do while you wait for that appt. There are helps here, including wise advise to keep a log on what you do, eat or take,(meds) and pain levels. You can find it on this site. This can help you and your doctor devise a treatment plan.
Many have similar symptoms as you describe, I'm hoping they will chime in and help you more.
I have crapping legs badly, knees throb, stiff sore arms and hands, aching back, neck, shoulders. I just ache everywhere but I don't have twitching, but my hands are shaky, but that may be a side effect from a medication I take. Id try not to worry. Fibromyalgia has many symptoms and not everyone is the same.
If there's a muscle, I've had a cramp in it. At the end of the day, my legs can cramp so bad that even putting my full weight into a stretch isn't enough to release the spasm. Often the muscles in my feet cramp to the point that my toes cross over each other, and some bend back and others forward. I'll get cramps in my ribs, back, neck, even face.
Things that help me: drink enough water, take magnesium supplements, use a heating pad, and stretch regularly throughout the day.
I also get the random twitches. Some twitches are the eye lid twitch kind (quick, rhythmic, tiny movements). Others are like the muscles are trying to do the "wave" (slow, longer lasting, and moving up and down a large muscle). This wave kind I get if I've overdone it that day.