I'm sure you can focus. And once you do, stay focused!
It's scary. I've got nothing to be afraid of-- or so they say, yet my mind thinks of every possible way to tell me that I'm not ready yet. I'd like to think of it as excitement, though. Sounds less serious. :P
Parting with people you've been with for half a decade also comes into mind, but I'm not attached to a lot of people enough to depress me. I guess it's sad, but I know there's nothing I can do about it but move on, and try to keep in touch. :3