It would be good to take advantage of the recent changes, splitting the reverse into a separate test. In theory, you could do a reverse test every day (obviously better to learn it first so you have a chance).
Your instructor should be able to teach you the reverse so that you can do it by rote. Line up as far left as possible between A cones. Right hand down 360 degree turn and reverse until you see the marker (2:40 in this video youtu.be/1RQOWQJzMow). Then left hand down until the cab is behind the trailer. etc. And do you have a telltale on the mudflap for how far back to go? Is that not how you’ve been taught?