Newhope, I am glad to hear your preparations for the race are going well!
It sounds like you are excited about the race, and I remember that feeling well. In fact, I could never sleep very well the night before a race. But--this is very important--it doesn't make any difference. I always did fine in the races, as long as I was prepared. One race was in New Zealand, and I didn't sleep on the overnight flight to get there OR the night before the race, and I still survived even with TWO nights of almost no sleep.
The worst thing you can do when you can't sleep is worry about not sleeping. Just know that you'll want to get a good night's rest before the race, but your performance in the race depends more on your preparation and state of mind than exactly how many hours of sleep you get.
Now, go get 'em!
--Coach CF