Can anyone please PLEASE tell me how to get rid of this??

At night i get this seriously weird feeling in my foot/ankle/lower leg- just the right one- and i just have to keep moving it to try to stop the feeling. Its so bad that it is keeping me up all night. I had it with my last pregnancy too, have never had it while not pregnant.

It set in much later last time and i didnt find a way of getting rid of it but it was only this bad at the very end ... im only just about half way now

Does anybody know what it is and how to fix it or even ease it enough so i can sleep?