Playing computer games when I should be studying

I have lots of things I should be doing. I should be working on my qualifying exam, which is this long paper which has to be researched and all that stuff. I am writing it, but it's pretty slow. Also, I should be constantly designing new experiments, and recruiting subjects, and running in my own experiments. I am doing these things, but it all feels kind of half-assed. What I'm all about is playing with this WWII strategy game I downloaded a couple of months ago. It's really hard to stop, and I've wasted many, many hours playing with it instead of reading/writing/programming. I am supposed to be a grownup doing work, not a kid playing video games. I am completely and hugely an idiot.