zoso-
your attitude is great. keep it up. i went through nearly the same exact thing with my gf even before the hard drug abuse. things started off great, but like a switch everything changed. when she finally put put the daggers in, i was dumbfounded, hurt, and confused. so i read up on stuff too, and when i read the book "help, i am love with a narcissist" everything made sense. i do believe she has personality disorders. after some time, a switch in me changed and i could see in her all the things you are saying about your girl. i git right back on my feet and was liking life just fine. over a year later she made contact. i thought, hell, i'm way over her, besides, she's crazy, i'll never get sucked back in so it's ok to have contact.......
.....holy smoke was i wrong. fast forward 2.5 years later and i am here today. and it took me a year and a half to really understand what i needed to understand. so i think it is great you are seeing it the way you do. do not only no contact, but just dont let your guard down later because those people are masters at manipulation and now i dont know what it would take for me to ever think she has truly changed for the better.
you sound like you are doing great, and at some point it will barely be a thought to you