Preliminary exam in communication

Tomorrow is my preliminary exam in communication speech already. It will be an oral test, that is, I have to give a speech and will answer questions. I am kind of nervous. The past days, I've been trying to study, but nothing is happening, as if my brain doesn't cooperate. I had a headache earlier today. I planned to sleep early so that I can wake up really early tomorrow, but I just cant sleep. It is so hard to sleep at a time your not used to. I am worried for tomorrow. I don't know what I can do. I can't fail any of my prelim exams. I need more time to review, but I don't think I will have enough time. I just hope a miracle will happen tomorrow.