Sorry to hear about this latest twist on things. When you are feeling up to it, maybe you can share more with us as to what happened / what she said. This must be really hard right now, since I know how good things were looking. More than that, the kind of reconnection you've been describing for the last couple of weeks sounds quite genuine and heartfelt on both your parts. This makes me think that something--like fear--has triggered this apparent 180 for her. I'm thinking like some other posters are suggesting that this could be that BECAUSE things were feeling positive, it just freaked her out that it was moving fast. The idea of actually moving back together was probably daunting. Who knows--maybe she had a dream or something or it all just overwhelmed her for a bit and she panicked and told you this.
Remember, you are still in DB mode!! Everything you've done to get to this point is still totally valid. I'm not convinced this is it...there are some other pieces missing here. Keep us posted and hang tight. We're here for ya.