From what you describe, it sounds like you are experiencing msuscle fasciculation.(or "jumpy muscles").
According to the National Institute's of Health Medline, there are multiple causes for this phenomenon:
-Diet deficiency
-Drug overdose (caffeine)
-Drug side effect (such as from diuretics, corticosteroids, or estrogens)
-Exercise
-Twitches not caused by disease or disorders (benign twitches)
---Often affecting the eyelids, calf, or thumb
---Normal and quite common, often triggered by stress or anxiety
---Come and go, and do not last for more than a few days
These nervous system conditions can cause muscle twitching:
-Amyotrophic lateral sclerosis (ALS - Lou Gehrig's disease)
-Damage to the nerve that leads to a muscle
-Muscular dystrophy
-Spinal muscular atrophy
-Weak muscles (myopathy)
Symptoms that suggest a nervous system disorder include:
-Loss of, or change in sensation
-Loss of muscle size (wasting)
-Weakness
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You mention fibromyalgia, which suggests you also experience what you think might be fibromyalgia symptoms. Perhaps you are also thinking of sensory integration disorder?
One area you can investigate for both of these conditions is mineral deficiency, especially magnesium but also calcium and potassium.
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Here is information on the early and later symptoms of magnesium deficiency, also from NIH's Medline. It goes on to provide dosing guidelines:
Symptoms due to a lack of magnesium have three categories.
http://www.nlm.nih.gov/medlineplus/ency/article/002423.htm
Early symptoms:
-Anorexia
Apathy
-Confusion
-Fatigue
-Insomnia
-Irritability
-Muscle twitching
-Poor memory
-Reduced ability to learn
Moderate deficiency symptoms:
-Heart (cardiovascular) changes
-Rapid heartbeat
Severe deficiency:
-Continued muscle contraction
-Delirium
-Numbness
-Seeing or hearing things that aren't there (hallucinations)
-Tingling
I hope you find this information helpful. No doubt you're not getting restorative sleep, and it's wise to try remedying this.