It always bothers me when I read posts from people I consider 'young people' barely into adult age.
I'm transgender, but I am also a parent.
And there is no excuse, non whatsoever, for treating your child the way you are being treated. And I say that as a parent.
Horizon, your father is failing miserably as a parent. You don't NEED proof, you only need to tell him, that this parent (me) is disgusted with him. He's a failure as a father, he has failed you, his love is clearly conditional, and it is clearly not as genuine as it needs to be.
My son for my 50th birthday, penned a message to me, that was saturated in complete acceptance and 100% love. I have never felt more proud of him. There is nothing I wouldn't do for him.
I just wish your father could say the same, that there wasn't anything he would do for you, including understanding you and not demanding 'proof' of who you were. He clearly has no idea who you are.