I'm the last person to comment on this topic, but here goes...
I firmly believe that you can still love her even if she doesn't love you anymore. And you can - no matter what happens - treat her kindly and as a friend (if she'll have you), and always be willing to accept her back if she leaves. Love doesn't have to be all-or-nothing. It doesn't have to be a mirror image.
And the same goes for acceptance. She might still love you, but be unable to accept you. But that doesn't mean you can't accept her. On the one hand, it might seem very difficult to accept someone who truly has issues with who you really are, but on the other hand, see it as an opportunity to show (over time - it might take years) another person that transgendered individuals are not something to be frightened of or ashamed of. Then she can pass that on to her friends, her family, and you'll have done something amazing to break the cycle of exclusion that hurts so many TG individuals.
I'm right there behind you, waiting for my turn on the "oh f**k, did I just make the worst decision of my life?" rollercoaster.