I think you did a GREAT job!! The shadows are all in the right place, even!!
I don't use pencil, only crayons and ONLY the ones from Stampin' UP! (I'm a demonstrator) and I get great results EVERY time.
I teach a hands on watercolour class and usually people come away from it saying they didn't know they could do that.
You could try rubbing that first streak on scrap to get rid of that darkness.
I think maybe with a bit more blending, your image would be just PERFECT!