Instead of focusing on the negative by keeping a running tally of bad stuff - you could also just let it go…
Do an examen prayer for a half an hour before the confession… and then confess what you could remember… and, since you’d be deliberately intending to forget something, you could explain that you are sorry for anything you forgot and missed - perhaps even explaining why you would want to forget a lot of the lesser stuff…
I know that method may not appeal to some people, but, while I love confession perhaps as much as communion, I try to leave room to focus as much as I can in acting upon a positive expression of the virtues… because there is a positive side to our religion that scruples can hinder…
btw, if you are going to mass, you dont have to go to confession for venial sins, since Priests have told me the Confiteor will cover venial sins…
The advantage is, if you can get away with just confessing at the Confeteor, then you can save room for someone else in the confession line…
No kidding… Some people do need more time at confession, but, then, some scrupulous people, who actually just want Spiritual Direction (which is different than confession), may take up a lot of time, when they could just say the Confiteor and then see the Priest at a more appropriate time for Spiritual Direction…
I’m not trying to dissuade you from confessing or receiving a sacrament… just urging you to look at the positives… so you can receive all in the right way and for the right reason…