This topic speaks to me because honestly, I'm the most afraid of my father's reactions to my transition as well. With that said, I've come to terms with a few things after thinking about it.
No matter what your dad says, or how he treats you, he'll be your father. That isn't going to change, because its a fact. But..that doesn't mean you have to let him into your life if he won't accept you as you are. I'm not saying to stop talking to him, but I am saying that there will come a point when he'll either come around, or you'll stop wanting to associate with him and his negativity. Perhaps I'm biased because I see myself in this position in the future, but still. Think about the people who do support you, and focus on them. If you're dad is going to come around, it will be on his own time. Make sure he has the information he might need, and make sure he knows he can ask questions and talk to you if he wants to..but beyond that, there's not a lot you can do.
With that said, good luck. I hope your dad comes around.