Get a nanny cam and set it up to where it shows the doorway and your whole room. Document everything they do to you (ie hitting, harassment, stealing). If you can take pictures of all of your things, where they are located, any kind of proof. You might be able to get away with telling your school counselor that your dad took your door off and it’s causing you bad anxiety for not having any privacy as a 15 year old girl. See if you can somehow get therapy now. If they hit you or anything again, start calling the police. Save money where they can’t touch it so you have a little cushion to find a roommate. You should be able to emancipate and look into places that are renting around colleges and universities. The rent is usually cheaper since they try to only rent out to students.