Having looked at your posts on this thread, and several of your last ones, it seems as though, with the best of intentions on your part, you've let her get away with becoming tyrannical.
As someone with a lot of neurodivergence in my family, I know how difficult and rejection sensitive teens can be (ugh!!), and how you have to approach situations carefully in order to not set them off (tying yourself in knots!), but the behaviour she's displaying isn't just autism, imo, it's a huge helping of being a spoilt brat with a side of autism.
I don't know where to start unpicking the tangled knots, but some thoughts that might hopefully be helpful?
No, you shouldn't have lied to her about her autism assessment, and I didn't catch why you thought she shouldn't be able to consent to it? Or be aware of it? I also can't remember if you've outright said that you are sorry you didn't inform her, and you should have asked for her consent? But you can't undo that, so no point beating yourself up. You did what you thought was best.
Have you asked her "is there anything traumatic that has happened to you that I don't know about?" As a pp mentioned, her insistence she's so traumatised makes me think it's possible something has happened that you're not aware of that's been eating away at her.
This may be bad advice, but I might try telling her that ultimately it doesn't matter if she's autistic or not, because it's not like there's any treatment for it. So if she believes she's not autistic, then you're happy to accept the diagnosis was mistaken, although you sought it in good faith.
But I'd tell her that her actual behaviour - not getting her education, not having a job, sitting around at home all day like a lump - is not acceptable, and as a young adult, she needs to start doing more.
If she doesn't feel ready to work or study, then write her a short list of itemised chores for each day - vacuuming, clean toilet, dust living room, do dishes, prep dinner (not necessarily cook it) etc - and tell her that you expect them to be done when you get home from work. This is something my mum did with me when I was a young teenager, haha.
It gets her doing something to lighten your load and keep busy. If she does it, praise her for doing it. Yay, she's such a huge help, so amazing! Then give her more to do.
Tell her she needs to pick a course to do by the end of the year (or within 6 months, or whatever), and then stick to that. Be enthusiastic and excited about the possibilities, but nag her about it.
Get your husband to do more.
When you're stressed, tell her that you're a human being too, and you already do so much for everyone, and you're exhausted, and you can't deal with her shit when you feel stressed - and then get DH to deal with her. Leave the house and go for a walk. Remove yourself from the equation, because you keep pandering to her. But equally, do fun, focused things with her - some nice mother/daughter activities or days out, so she sees that it's not rejection.
Disclaimer: Most of the bits of advice are variations on things that have worked on me/my kids. Success rates may vary! Use at your own risk!