Anna has accepted that she's a slut, and that means people like Jeremy have less and less leverage over her. In Chapter 1, she didn't want to be that way and worried how other people would react if they found out. But as soon as she decided to do porn, and work as a bar whore for Patrick, it became inevitable that they would. And since she made the choice to do those things, it means she's crossed a threshold, where she can't be in denial any longer. She's doing all this stuff, not because she's being forced to do it, but because she wants to. And once you recognise that, then everything changes.
Anna has always been a strong person, and without her condition, she would naturally have resisted all the blackmail and coercion that takes place during Chapter 1. But her condition makes her weak, and so she gives in to it, and as result she becomes a slut. And once she accepts that about herself, that weakness just evaporates, and with it all the leverage to blackmail her. Her condition has changed her as a person. She no longer believes that being slutty is bad, and she doesn't care if people think she's a slut, because she's making a ton of money from being one.
