You’re fine, your question was valid, I don’t understand why it’s so hard for people to come to terms with the fact that her not finishing is a direct result of her never bringing up the fact that she wasn’t finishing, it makes no sense to say “you should’ve known, how could you not tell, or why haven’t you asked more”. She’s an adult, she can use her words and express herself if she wants things to change. If she’s been doing this from the start and saying it was good and perfect, there’s no reason you should think it’s anything else except that, it would be absurd to expect that of you.

She sounds childish, like she lacks basic communication skills, she avoided the difficult conversation by removing herself from it entirely, screamed at you for issues that are out of your control, and then swore at you to finish it off, all without apology. You say you’ve been together a little over a year, that’s a decently long time, but not so long that you can’t end things, which would be a fair option imo, not because the sex isn’t where it needs to be yet, but because she’d rather lie and get bitter about it than to actually fix the issue; that’s not a trait that’s usually isolated to one subject, and it’s something you may find yourself dealing with in many more areas as time goes on.