You're not going into the gym today, but that doesn't mean you can't start mentally preparing for what you're doing tomorrow. Go through your set-up routine in your mind, and try to think about how each rep is going to feel. You've been under heavy weight before, so you know how hard you're going to have to push.
If you're feeling nervous, good! If the weight doesn't scare you, then it's probably not heavy enough. Don't get so nervous that you're not eating, though. Get those calories in so you have plenty of energy tomorrow.