I'm super restless; what should I do?

I feel super sonic restless (no, I haven't been getting shots of caffeine) and even jittery. I have plenty to do (write an ethics exam, work on my dissertation, clear the clutter in my work space), but I'm too restless to do anything. I'm wired! And, I feel useless. What's the deal? Aaaaaaaaaaaaaaggghhhhhhhhhhhh.