Cats can play ALOT! Have you considered getting another cat, if not try to reprimand him every time he does something bad.. like spraying water or sternly saying "NO". The water thing scares my cats off to run away but doesn't really work well so I had to resort to lightly but firmly spanking on the butt and they get the point. Do not let them bite and scratch you, they will think it is ok and that is a hard habit to break. Hope kitty gets better!