You actually don't know how things would have turned out with this girl had you told her to take it slow, instead of the plain truth. Maybe in a few months you would have broken up because you wouldn't have been able to fully connect, or the infatuation disappeared. Maybe it would have been even worse then. Anyway, six months before or six months later, if you were indeed the one for each other you should have both felt it, don't you think? But you didn't, so your idea about what this relationship could have been or would have been it's incorrect, and circumstances had little to do with the outcome, especially because you played it fairly. I personally think that none of those two women was the right one for you or you shouldn't have had so serious doubts and for so long.
You need to rebuild your identity and this time around something much more stable, reliable and fulfilling. Relationships come and go in life and even the greatest love fades sometimes, so you owe it to yourself to build a strong, happy self with meaningful passions in life that may appreciate a nice compatible person when encountered but would not revolve all his being around her.
I think you're not supposed to learn about how honest or less honest you should be in a relationship through this experience, but to detach and redirect your energy on something that could help you (and others) grow as a person, something that you could be passionate about, and learning to leave gracefully something that wasn't meant for you. Maybe it will take you some time, but when you'll succeed you won't believe how good it feels, so much better than anything this woman or any other could offer you :-)
P.S. Sorry for derailing your thread, OP.