Hi there :) I've been through the same emotional roller coaster a couple of times, courtesy of "friends". So, I won't give you suggestions on how to survive the flames - let them burn! You are much, much stronger than that.
I only wanted to say - since you're already familiar with the behavior pattern of such people, treat them right from the start; don't let them draw you into their net, then you'll have to spend extra energy getting out. Keep cool and make them feel uncomfortable around you - they'll leave. :D