I'm not sure what you are going through is depression, buddy.
You are a std XII student. So, exams related anxiety is all too common.
But here are some tips to overcome this overwhelming stress you're going through right now.
· Always approach your exams with the mindset, that the exams are a means to test and improve your knowledge, and not a testament of your abilities. The only purpose of exams is to make sure you're making the necessary progress in your vocation.
· If you think of it as matter of life and death, or as something that puts you at a comparative pedestal with your colleagues, then you might land yourselves in trouble. Many do that, and go unscathed by the competitive stress. But everyone has different stress thresholds. So, beat the rut and the rat race, and study to improve your knowledge. The grades will take of themselves.
· Try and be a part of group discussions.
· Keep scribbling/making notes while you're studying. These notes invariably come very handy during your exams.
· Take frequent, but short breaks while you're studying. In these 10-15 min breaks, listen to your favorite music, call a close friend/family member who can divert your mind of the stressful exam situation, or watch something light, like an episode of 'Friends'. This will improve your focus and you'll register more data.
· Exercise for at least 20 minutes, even during your exams(whatever form of exercise you prefer).
· DO NOT try to cram in too many new topics on the eve of exams. Instead, try strengthening the topics you know.
· Make sure you're eating well and sleeping well. No matter how much you've studied, if you haven't enough sleep before the day of your exams, it might make it very difficult for you to reproduce it on paper.
· DO NOT go to the exams with an empty stomach. Keep a candy, handy in with you during the exams.
· DO NOT discuss the answers you've written/missed after your exams.
· Make sure you draw diagrams/illustrations wherever necessary. It makes a good impact on the examiner.