Oh my god, I don't fucking CARE!! Look, I can see you being pissed off at her, feeling that she's a psycho-bitch, etc. I would be pissed too if a lot of shit like that happened. However, I would try to just ignore her for forever, and then try to move on with my life. I've had people online totally fuck things up for me before, and yes, I was really pissed, part of me wanted to kill them, or at least for them to die. But, I moved on, I learned from it, and I don't associate with them anymore and I don't tell anyone I've never met face-to-face details of my life. I'm not trying to tell you what to do because I know that won't work. I barely talk to her anymore, anyway. She's not a big part of my life; she just happens to be a friend who I talk to on occasion just to see what's new in her life and all that. All I'm saying is, that even though she did things that pissed you off, and caused you to "waste 6 1/2 years" of your life; ranting about it like this isn't going to help. Maybe take a small amount of personal responsibility and realize that you made the exceptions, you tried to be nice to her, you decided to continue talking to her, and you invested yourself emotionally in her... basically, you put yourself out there and someone took advantage of that. It happens to the best of us; hell, it's happened to me plenty of times. Can I change other people, though? No, I can only change myself, and what I did was to close myself off emotionally to everyone online, and most people in real life. It sucks sometimes, sure, but it's better than being taken advantage of.
In summation, I can see that you're trying to warn me so it doesn't happen to anyone else, and I can appreciate that. But like I said, she's barely even a part of my life and I don't tell her shit about me. I hope that you find peace soon.