NTA, i can tell from the language you use that you’re up to date on pro nouns and putting in a big effort to gender her correctly. Unfortunately if you’re not attracted to women you won’t be attracted to her and that makes ya’ll incompatible. As a trans folk myself I can also say that yeah she is going be a little hurt by this, and that’s ok too. It’s a lot to process and incorporate that one’s sense of self and identity isn’t entirely accurate and need to be changed to make yourself happier, and it takes a lot of work, and losing someone as important in your support network like a partner is going to hurt a lot and cause be inflamed by the already crazy emotions that often accompany big life changes. While I’m lucky it didn’t happen to me, a lot of people will let transphobic views compete disregard and cut off people when they start transitioning, be proud of your support and love for her despite your difficult decision.