Here in the uk you are legally an adult at 18,but you can choose to live at home or not,and your own treatment options at 16 .As a parent i have never understood the mind set of jehovahs witnesses re blood,or alternative treatment methods that have no proven merit,and i know i would implore my offspring not to follow such a hazardous course.If all possible medical intervention had failed ,no one could blame you for trying anything,but until that moment arrives i wish you would reconsider what you are doing.
that being said, the good people on this site would never shun you for making an informed decision even if they don't agree with you,so keep on posting and let us know how you are doing.
liz