You can’t take care of a show unless you take care of yourself, first. You mention going to bed with a pen and paper nearby. I’d suggest that before you even attempt to go to sleep, you spend some time out of bed with that pen and paper, and clear your head by jotting down all of your notes, questions, and worries. Then put the paper aside, and do something non-theater related for a while (read a book, watch bad reality TV, call a friend who loves chemistry). Then try hitting the hay. In the morning, you can look at your notes again, prioritize, and be sure to delegate anything you don’t absolutely need to do yourself.
It sounds like you’re doing all you can to prepare, so be proud of yourself for that, and try to keep this experience in perspective. Your first show doesn’t have to be perfect, it just needs to be your best effort…and hopefully FUN, since SMing is far too much work if you don’t enjoy it. Remind yourself that when something goes wrong, it won’t be the end of the world; you’ll learn from your mistakes, correct the problems, and the show will go on.
Break a nail!