Same here, not Wendler, but I can relate to some extent. I pretty much never test my true 1RM so getting close to my 95% used to hold me back a bit.
What I’ve noticed is that working up to your TM (x1 or x3-5 reps) frequently and doing Joker sets helps building confidence and some programs call for this kind of work.
This is a newbie opinion, so take it for what it is - a newbie opinion.
For PR sets, you shouldn’t require any special kind of mental toughness unless you’re very strong. Determination, yes, mental focus of course, intention definitely, but you shouldn’t feel the need to tap into the darkest place of your mind to go through PR sets.
This is for a simple reason: if your TM is correct, if you started off light and progressed slowly, you had all the time to adapt and getting used to the weight. If the weights you’re using scare you, reduce your TM and start back building confidence with your submaximal work.
I tested my 1RMs when I started 5/3/1, I remember my deadlift 1RM was a shaky shit, six months later I was doing 9 solid reps with that same weight with about 2 slower reps still in the tank when I stopped the set - and not a single fuck was given, cause the work I put into the lifts 6 months prior told me that I had those reps in me, I wrote down everything, the numbers were clear and the feedback I got on every training session told me that I could push to that amount of reps.
Get used to it and get used to do clean strong reps, form will never be perfect, don’t go OCD on technique but at the same time don’t try to grind away until your spine snaps. Most of the training related stuff seems to have the sweet spot somewhere between common sense and stupidity, so find a compromise that allows you to progress and push while feeling confident and staying safe.
Random anecdote: I do front squats as my main squat, and I’m not great at squatting. Been into a full body template for the last cycle that had me squat 3 times a week, hitting TM x 3-5 once a week. That built confidence in squatting AND hitting an heavy-ish weight each time.
Yesterday I did the heaviest squat day in the Anchor phase, with PR set at 95% and possible Jokers. I cap my front squat PR sets at 5 and then usually follow up with Jokers for triples, so I planned that if I hit 5 good reps at 95% TM, I would increase 10% and go for a triple - that would have been the heaviest triple ever so far, to me.
Did 5 good reps at 95%, was fairly confident in doing 105% x3, probably too confident since when I unracked the bar I messed up my breathing (maybe pushed bar in throat) and suddenly got all dizzy, “soft” on my legs and felt like was a breath away from passing out. It was a scary sensation and the first time ever something like that happened to me.
Racked the bar back, waited a few minutes until I felt “normal”, then got up and did the 3 reps I had to do at 105% - got three solid reps and zero issues.
I knew I had those 3 reps at 105% because I assessed my 5 reps at 95%, plus all the work I precedently put into training sessions during the whole cycle.
At the same time this taught me that confidence is ok as long as you don’t go full asshole and screw your setup. Live and learn.
If the bulk of your submaximal work is done correctly, if you increase the weights progressively and slowly, you will be more prepared for heavier sets.