You feel stressed about your schoolwork. Many students of your age have this problem. You are not alone. You need to study hard. However, to study better, you also need to relax yourself. So it is important to manage your time better. You must achieve a balance between work and rest.
Another cause of your problem is your parents. They care too much about your marks. You had better talk with them about your stress. The problem of stress gets worse if you keep it only to yourself. I think they will understand and help you after they know your stress.
