Cobra Commander, I know how you feel. The shitty thing about these situations is that she isn't required to state the reasoning for breaking up with you. SUCKS, especially during those long nights of "What if" which can play back and forth in the mind for hours...
I had a similar thing happen to me a few years ago where I hit it off really fast with a girl a few years older than me. A week later, bam, "See ya"! The most I can gather from what went wrong is that she was smoking hot, she offered herself to me and I didn't bang her. (I was getting around to it!) Anyways, she had the courtesy of letting me know she was
looking for something else though she never answered "Why?".
That's simple now...I am not what she was looking for.
At the time, the ordeal left me scratching my head and very confused. In regards to your situation, I believe she found out that she wasn't interested in you, but didn't want to be too blunt or hurt your feelings unnecessarily. Lord knows that breakups can turn ugly and dramatic very quickly and its probably best that she did what she did...
I am not at liberty to say whether this experience is a good/bad one, but I can only tell you to keep at it with searching! You'll eventually find the right gal. Good luck to both of us actually.
Jam it back in, in the dark.