Usually when they start looking for causes for this type of thing, partly because there are things that have to be ruled out, and partly because they don't want to unnecessarily concern the patient and family. I can give you some general ideas, but that is just what they are, general ideas. This has to be guided by your doctor and any specialists you see. I would suggest a rheumatologist. Your symptoms are particularly similar, I think, to an acquaintance, but I want to confirm this before I mention the particular problem.
It is hard to say how to relieve the symptoms when it isn't known what is causing them. However, plenty of rest and plenty of water always help. Also, even though you are feeling weak, you really must keep moving as much as possible. If you can't get out of bed on a day, be sure to move all of your joints while you are in bed. Maintaining the ability to move your joints will be very important to your recovery. It could be that the doctor could prescribe an anti-seizure medication to help with those RLS type feelings, but that could mask symptoms that would ultimately lead to a diagnosis. Perhaps a muscle relaxer would help some. If all you can do in a day is get out of bed and walk around the house, do that. You don't want to push to the point of total exhaustion, but you need to keep moving as much as possible.
If you are wanting to research this, this site has a general list of many neuromuscular diseases. I need for you to understand, though, that many things have similar symptoms, and you can perhaps find a direction to look here, but you can't make a diagnosis.
http://www.mdausa.org/disease/40list.html
Various myopathies are also possible.
I'll be back later with more.
Let me know if you need further information. Please remember to click the accept button if this information is helpful. Thanks. JeanRN