Open Question: Why do I feel so restless?

Ok, so i haven't worked out in a long time, on sunday i went for a walk and did some lunges until like my leg started to cramp. Then on tuesday i went running and did some more lunges. Last night my arms started to feel really restless and it was bugging me until i fell asleep. I woke up this morning and felt fine until i went on the computer..now my whole body feels really restless, like i need to keep moving my body..i feel like running nonstop. What's wrong with me?