Hi dear, I understand your difficulty in academic life. Do you feel the same in other activity, apart from your studies, Are you sure your study skills are proper and you are able to concentrate better. If all these is fine it means you might be anxious of examination. You need to work on stress level. Also during examination having healthy food and proper sleep is very much required. If you can't manage your stress,You can approach psychologist for better guidance. Take care have confidence. Do not lose hope.