I'm sorry you are feeling so bad. Most parents will not give their teenage children the option of not going to school. While they can force you to go to school, they can't really force you to work at your studies. So you are going, physically, but you are not participating in the academic work. It sounds like you may be unhappy in your social relations at school and feeling depressed. This is something that should be discussed with your family doctor. Seeing a therapist might help you.

Is there something going on in your home that gets you demoralized?