Dear Student, 12th board exams are a phase of life but not your life, it's normal to have stress before exams because it motivates us to study well. But excess stress leads to irritability, headaches and multiple symptoms. U need to stop planning about your exams and plan for the next hours. Have short term goals like I will read 2 chapters in next hours. Don't prepare schedule for a week or so. Eat healthy don't strave. Manage your time well, stop using mobile internet and video games. Don't campare your studies with other students. Read in chunks of 20 mins and then take 5min break. If you r getting scared of exams and feel will not be able to attempt it meet a psychiatrist.