Firstly, take time to prepare your notes in the best way that works for you. Don't think you can get away without revising because you'll probably just end up making things stressful for yourself during the exam which no one needs. Secondly, find comfort in knowing that you have power over your exam, perhaps more so than you ever have. And lastly, have a cup of tea or hot water bottle by your side in case you feel stressed and dehydrated during the paper. Hope this helps