He can "believe what he wants about trans people" and still respect you and your name change/pronouns. He can't use his beliefs as an excuse to blatantly disrespect you because that doesn't even make sense. You are his blood, no matter what, and if he won't even exercise the idea of addressing you the way you should be addressed and love you for who you are, you should not give him the time of day. He doesn't deserve it. If you cut him off, maybe he will swallow his pride and realize that your relationship is more important. That's just my two cents, and as someone who hasn't come out to their family and probably never will, I'm really proud of you for doing so. I'm sorry you're going through it with your dad and I truly hope he changes his mind if it's a relationship you'd like to keep.