Good rant. Unfortunately, at 16 you are not legally capable of making your own decisions on legal and medical matters. If your parents or a guardian ask and do the paperwork, the results might well be different. It is not prejudice against trans, it is protecting minors -- even if you do not want that protection.
You could become legally emancipated (declared an adult before 18), but if so, you could not put any of your medical expenses on your parents' insurance.