For that which it may be worth:
Assistance work, if it was any good, helped get you to the prom. Don't be too enthusiastic about throwing it away, but be mindful of its ability to change the subject. Tapering back usually helps.
Get a more "how-I-will-lift" mentality. Approach and set up like you think you will at the contest. Sets of 5+ might be fun, but throw in some meet like singles so that you can relieve your mind from thinking about what needs to go right, a single becomes automatic, it lives in your lower brain. Now your upper brain has the bandwidth to fix what might go wrong like in a squat "I'm helicoptering, okay, slow down, get my shoulder into it, straighten, good, now drive."
Matter of fact.....when you are just lying around and visualizing your lifts some 1 zillion times between now and then (everybody does that, right?), seeing yourself perfectly nailing your attempts, also throw in a screw-up and SEE yourself fixing it and still winning.
On singles, you don't have to be crazy heavy, but up around opener weight at least. As I said once (sorta, I think), your first attempt should be something which you can normally triple with a full bladder since, and if this is your first meet in a suit, as soon as the straps are pulled up you will have to pee. Heavier singles if you know what you are doing. Or are really neurotic. Or both. Other.
Get into the contest environment. Get used to using the gear. See how long it takes to get into costume. How long can you stand being in full costume. Can you get better used to being in it somehow (sitting with legs out straight so that your shins turn less blue, putting your arms on your buddy's shoulder like you are frozen in a conga line to keep your arms alive, other.) When you deadlift do you feel better to have the straps pulled up from the front, better from the back in the squat? Where do you need/like chalk? Who's gonna wrap your knees?
At a contest, attempts are timed. Get used to a clock. 1 minute from bar loaded to the appropriate point ("squat", "press", starting your pull).
Anyway, when you get used to the annoying stuff, make your execution automatic, the rest of you can attend to business.
If this was not what you were asking for, then we will file this under the 5% of stuff I post which is crap.