A gentle reminder: you're allowed to break up with anyone for any reason. It doesn't matter what it is. You don't need permission and you don't need a "valid" excuse. If you think/feel that the relationship is no longer working out, you are well within your rights to end things.

Having said that, I find a lot of your girlfriend's behaviour to be very suspicious. Like what some of the other comments have already expressed, I think she's being manipulative. The most jarring part is where she says she "appreciates your openess to growth". She's implying here that there's something wrong with you for every opinion that you've expressed in the past that relates to this topic (even though it doesn't seem like she's ever expressed an opinion to the contrary).

The next thing that's concerning is that she's blatantly refusing to tell you how long she's felt this way/had different opinions. I'd like to be clear that having different opinions from your SO doesn't necessarily matter so long as both parties are on the same page with how they want the relationship to be. However, this particular situation seems very suspect.

I'm personally of the opinion that she knew all this time and was waiting until you fell for her before she dropped the bomb. You can try giving her the benefit of the doubt and assume that she's only just recently come to terms with this new identity but, then why is she refusing to be open about it with you (which is the same thing she's criticized you about -- not being open enough).

Also, in one of your comments you said that she said "you felt safe to she your thoughts and beliefs". That's the biggest red flag right there. She's basically telling you that you're no longer safe to share your thoughts. You shouldn't have to feel like your "walking on eggshells" every time you're talking with your partner. This whole thing screams toxic to me from her end.

And yet another thing to add. Let's assume for a moment that she isn't being manipulative and she's struggling with her identity. This doesn't excuse the fact that she isn't even trying to speak with you! She's already acknowledged that she knows all of this would be a lot for you to take in yet, it doesn't seem like she actually made an effort to help you through this. I don't know how often the two of you speak with each other but, I'd just like to point out 1 hour is approximately 4% of the day and 30 minutes is roughly 2% of the day. You're telling me she can't spend two percent of her time talking to you even though you're clearly distressed about all of this. It's one thing if you guys talk regularly and she needs time to herself. But this doesn't seem to be the case. It seems to me like she's pushing you away and starving you from attention.

I get that you love her but, you really shouldn't neglect taking care of yourself and your own mental wellbeing. I think you should seriously consider cutting your losses. If you do choose to stay with her, be very careful about trying to manipulate you. If you chose to leave her, be wary of her trying to play the victim. She might lash out at you by saying that your discriminating against her for being non-binary. And to that I say, "read the beginning".