You also can say:

  You can t keep me from doing what I want (to)/what I love to do. 
  You can't keep me from doing that/this.
  You can t keep me from doing anything I please/wish/want/decide. 
  You can't keep me from doing whatever I want since I am over 18 years old...
  You can tell me that I am making a mistake but you can't keep me from doing it anyway.
  You can't keep me from doing things (I want/wish).

   And, obviously, hundreds of others ways, let´s wait and see.