Having read this a couple of times. I think that the point you are trying to make is :
That every time you took a left turn you took some of the opposite lane on the exit road. Correct me if I’m wrong.
Depending on the way the junction is laid out, often it is necessary to go over to the right of the lane along the line so that you have a better angle of approach and do not have to take much, if any, of the opposite exit lane. If it is a sharp exit bend then you should make sure both directions are clear and take enough of the lane to make the manoeuvre without overdoing it. As soon as you are round the bend get back into your own side of the road.
I am sure one of the resident trainers will be along to correct me shortly. Just going from what I remember from my training and test only a few weeks ago.
Sorry to hear you failed and better luck next time.