As others have said, take a flashlight and crawl into your sleeping bag, others wont see the light too much if it is in your sleeping bag.

I'm sure people will be understanding about it though. If your really nervous I bet they will let you have a light on for awhile And who knows, maybe someone will be in the same boat as you! I know when I went to camp there was three people in my cabin that were freaked about the dark!

I hope your camp goes well