Panicking

Is this C4? Today I went through the textbook, doing all the mixed exercise questions I could, allowing half an hour for each chapter, then had lunch and did a past paper. My grade has improved by about 10% from just doing that. Just keep doing questions, but make sure you get a good night's sleep and keep calm tomorrow. Don't revise or talk to anyone before the exam, just go somewhere quiet if possible to wait and collect your thoughts. Good luck