What is this?

I had a horrible time sleeping last night due to a very uncomfortable feeling in my legs. It sounds like Restless Leg Syndrome but not sure plus I don't want it to be. I had this urge to keep moving my legs because they were sort of achey and twitchy and just short of cramping. I might add that I have ramped up my walking this week and it has been very hot and humid. I have been sweating ALOT but I take my mega jug of water with me on my walks. I also hydrate before I go and when I finish. This evening when I got home I had about 12 oz. of low sodium V-8 that is LOADED with potassium immediately.

With all that said...what the hell is it???!!!!