You cannot make that decision at this time. You may be a mature 16 yo, but under the law, you are a minor. If you want to make legal decisions for yourself, you must petition the court for empancipation. Otherwise, you are not in a position to simply decide not to come home, and you place your friend and her parents in an incredibly difficult position. If you truly intend to make progress as regarding your education, health, home and social environments, then you have to be able to show to the legal system that you are prepared to take care of yourself. Otherwise you will potentially subject your friend's parents to kidnapping charges, and your parents can physically force you home through law enforcement.