This can be a tricky situation. Some people who are set in their beliefs will just fight harder the more you try to inform them. I'm not suggestion that this describes your father, but the "ungodly" and "gay" comments are blatantly hurtful, so he's hurting too, and so rejecting it without reason.
If your father is not open to being informed about being transgender, then subtlety could be the best approach. That is, avoiding all confrontation on it, avoiding all discussion, and just continuing on your way and showing that you're happy and responsible in this and in life. There is never any guarantee, and it may take time, but he will eventually notice that you're in a better and happier place. What he chooses to do about that is ultimately up to him, but any caring parent should see this as positive and then accept the situation.