Tips on HRT with a transphobic parent?

I am 16 years old, FTM, and living in a state where it is illegal for HRT to be prescribed to minors. I am lucky enough however to live close to a state that I can legally drive over to and get my Testosterone. I actually have a friend who is MTF and that’s exactly what she did.

However,

Although my mother is very supportive of me, my father (who I do not live with and am in very limited contact with) lives in a state where a parent allowing a minor access to HRT is considered child abuse. Our biggest fear is that if I were to start T and he were to find out, he could take it to court and possibly gain custody of me.

We don’t know the extent of the law. I would greatly appreciate any links or keywords to search for when looking for more information on this. Thank you to anyone willing to help.