Great tut. The piece works beautifully stylistically, but if you're trying to draw a real woman's portrait this way the anatomical problems might make the result unrecognizable. You talk about the nose being your worse nightmare to paint, and it shows- you've just given her a tiny child-sized button nose lower than it should be. Also the neck is a bit on the long and skinny side.
With this kind of front-on portrait, the eyes should be halfway down the head and the nose should end halfway between the eyes and and the bottom of the chin. You have the eyes too low and the nose even lower, so this throws everything else off a bit.
That said, this is a great insight into your painting process and thank you so much for making it!