I agree with the others that you should move on. In fact, I would suggest that you send her a text cancelling your next conversation. Wish her well and leave it at that.

I think many of us have a certain somebody in our past that we will always wonder about, but IMO, our memories of that person and the relationship are often HIGHLY romanticized. If you and your ex scratch this itch, you could find out that the reality is vastly different and, in the process, tragically hurt yourselves and other people.