It sounds like that "it takes two to tango" stuff might have been something she harped on since you seem to bring it up when you're talking about the awful things she did to you? But like... that only goes so far. You didn't make her make the choices she did, you didn't make her treat you in a certain way. If she was so upset about your behavior, she could have broken up with you! Instead, she punished you for it and it sounds like she did everything she could to make you believe that if you just weren't so whatever, she wouldn't have to be awful to you. Spoiler alert: insisting the other person MUST be at fault too is an abuser tactic. I can tell you from my own experiences with someone shockingly like Ariel that you could have poured every ounce of your attention into her and bent over backward to meet her demands and still gotten fuckall back, and she would have had lots of reasons for why you just didn't deserve anything more than she felt like giving you and why she had to control your time and relationships. There's no way to win with people who behave like this.