I cannot believe that I actually wrote and put my original two posts out on the Forum. It was a pretty dire few hours. On the other hand I'm pleased if it has enlightened even one person to how this condition changes lives, and relationships. I'm so lucky that my dh 'goes with the flow'. And knows if I'm not in bed that he'll find me somewhere 
Thank you all so much. What wonderful responses, I am surprised at how many.
I eventually got about 3 hours sleep and feel a lot better, the symptoms are generally at their calmest around morning time. Generally the condition follows a circadian rhythm i.e. are worst at night. But actually can occur at any time, in any part of the body, at a time of rest.
I'll try and answer everyone's excellent comments.
This could be long and I hope that you wonderful folks stay with it to the end....
Luckygirl I already take Requip for the symptoms. Unfortunately one of it's side effects (or else it's a component of RLS) is that it can be 'alerting' making sleep difficult. Yes can be due to the iron deficiency... usually the deficiency is the ferritin serum iron, i.e. the iron in the brain.
The anti seizure drugs are now being considered as first line for RLS even over the Requip. I've never tried Carbamazepine, or any of them, as I've heard of awful depressive side effects.
Yes, many medications can cause/trigger RLS, antidepressants, antihistamines, Benedryl, and each person's trigger could be different. The condition can also be genetic.
Indinana Sometimes the symptoms are under control and it's just the alertness/insomnia, but with just the insomnia at least I can lie in bed and read.
Galen thank you, I have a magnesium spray but don't see much benefit. I will try anything, within reason
annsixty yes, there are support forums. I belong to one in particular which is excellent and thorough, and very supportive. It is actually the discussion board of The RLS Foundation which provides research funding for the condition. The Foundation's medical board is made up of eminent experts in the treatment of the condition, one of whom responds speedily to emails seeking help and advice.
Mariclaire your link is excellent, one of the best I've seen, great for explaining to non sufferers exactly what RLS is about.
Just to note: many (most) GPs are not up to speed in the treatment of this condition, and indeed neither are many neurologists. After all, it is not life threatening in itself. My GP had to look up the information on proper treatment for a severe sufferer on the web site of the RLS Foundation previously mentioned. Fortunately my GP was happy to be guided. He is willing to supplement my Requip medication with Cocodamol and/or Tramadol Slow Release.
Sorry to have made such a long post - I'm almost embarrassed at my verbosity - thank you all. 
It would be great if even one sufferer of RLS gained a glimmer of useful information.