I agree with oldrotorhead as well.
It seems like you don't have a handle on it, let alone any confidence.
I suggest a change of attitude from "groan..." and $hitting yourself to being a bit more positive and practical:
"OK, I haven't got a handle on this yet, and I've just got to do as many as it takes until I do."
More training man, do as many as you have to. Everyone had a problem with autos at some stage.