Oh, dear - sorry, but I think her behaviour, as a teacher, was very bad. It was up to her to find different ways of teaching you - it was not up to her to keep plugging away at you in exactly the same way and expecting a different result. She should have kept going using different methods. To pack it in - or not - should be your choice. I speak as one who often comes up against people who've had it drummed into them that they can't draw. And I have to find ways to show them they can if they really want to.
Blimey. That turned out to be a bit of a rant. I've not had enough coffee yet this morning. It's making me ranty.