When I posted that earlier comment I thought everyone might disagree with me. Heading towards the end of the school year with so many events going on, my DC have been on my mind constantly. I can't begin to imagine, where I am now, a day my daughter could do this to me. But I'll bet that you, @Moomoola, were in a similar position when your DD was 12 too! I can't imagine ever having to say anything as difficult as I advocated you did to my own DD.
But yesterday I had to talk to my DD about how important it was that she spoke up for herself, believed in herself as a good person, and defended that if anyone ever questioned it or her. Yesterday I was telling her that exploitative people can sense if they can push and control people and she's at risk of that happening if she doesn't understand that she is entitled to be treated decently and with respect, and she must demand that.
It made me think it's critical that they see us, as mothers, doing the same. In a way, your DD is modelling the exploiter's methods from 'x' and this cult. I do think that setting boundaries, and laying out your expectation she should treat you with respect is about more than just letting the line go slack. It's also about a calm dignified self-respect, which you hope she will gain as well in response to 'x'.
All this stuff going on in her head ... she needs to make room there too for accountability for the impact her shit has on others. If it makes her feel sorry for herself and rubbish, so be it ... she needs to deal with that. There's a difference between feeling rubbish because you have issues, and rubbish because you're upsetting everyone. She shouldn't be allowed to confuse the two or be protected from her own behaviour and sense of guilt.
In a nutshell, you really don't deserve this from anyone, and especially not those who supposedly know you the best and love you. It makes me quite cross. At some point you will probably have to make a stand for yourself alone, it's just a question of when. I agree with others that you don't have much control over whether she takes testosterone or not at this stage. So now is as good a time as any. But very easy for me to say. I totally think you should try and get away for some quiet free time as well.