ESH/NTA - I'm trans MtF and pre-op for some perspective. A lot of the trans community on Reddit will agree with me when I say that you are 100% entitled to your own sexual preferences, especially when it comes to the other person's sexual anatomy. That being said, the reason she's so upset is likely how you responded more-so than the fact that you rejected her. I do understand that you were drunk, but I would recommend apologizing for being so harsh about it and say that you really appreciate having her as a friend and want things to stay that way. If she still doesn't respond well after giving her some time to cool down, try to be understanding that it can be very hard for trans people because it feels invalidating of their gender. But even if that happens, you need to stand by your decision, and know that I and many other trans people also believe that you're entitled to your sexual preferences.