Yup, this is what girls do. Pretty much the EXACT thing that happened to me.... Things were perfect until the very second that they ended and she can't explain why she feels that way. Guys want to try and work out problems and figure them out, make things right... Girls just turn off like a light switch and it's game over from that point on with 0 bother to even try to salvage it because it's a wasted effort because they have no idea what they are even feeling or can't express how they got there.
@house, are you interested in buying it? it may be a good opp for you if you want to stay there.
If you need time away, there's a couch up here if you want to head north for a few days or something.