Everyone even Chuck Yeager himself, needs to learn the new skill set one piece at a time. If the whole thing is coming unglued during the pre-solo phase, that normally as an instructor means to me I'm asking the guy to do too much at once.
Ask your instructor to take care of the RT and maybe even the downwind checklist etc, for a few circuits or a few lessons or as long as it takes, so it unloads your mind just a bit and you can just focus 100%, on putting the plane in the right place at the right height and speed and power setting and config. As that starts to embed and you can do it without thinking too much, re introduce the RT and checks and start to develop the rest of the circuit situational awareness that you'll need prior to solo.