to break the cycle, you have to tell her to GTFO, and when I say GTFO I mean with authority. don't pussy-foot around and say "uuummm....eerrrr....I think, ummmm, we need to , errr have some time, ummmm, apart...", tell her with a clear and strong voice (without yelling or raising your voice) that you're sick of this relationship and the toll it is taking on you personally and that you won't stand for it any longer. obviously you'll interject with some details to elaborate this, but you get the idea. the main point is to let her know that you've had enough of this shit, and that you need to sort some stuff out without her insane distractions.