How can you get to sleep when you have to design a world?

I'm a writer trying to get some serious writing done these days, but it's hard to get into the story when you can't even decide on the basics of the world. I had a good writing session of 4000 words, and most of it was just arguing with my character about the way the world should be and how he can't do the things he wants to do because of how I constructed the society and metaphysics of the world.<br>He wanted to know why he couldn't use magic to solve his problems and I told him that magic was illegal. He asked why it was illegal, and I told him that magic was outlawed a hundred years ago because of how the emperor had used magic to cull cities of political dissenters. He asked what kind of magic this was, and I realized that I hadn't established the full extent of his powers, or the potential limitations. This copped a whole paragraph of self-accusatory garbage about how I was an amateur world designer and I didn't know the first thing about writing.<br><br>The next few hours of my life were spent thinking about magic. Writing pages of notes and deleting them, trying to come up with rules that were fair, balanced, and made sense. It led me to a thousand other questions about how my world was structured, and most of them I still haven't answered.<br><br>I'm not getting any sleep tonight.<br><br>And yet, I still haven't settled on a coat of arms for the imperial family.