Perhaps I should begin by saying I have resolved the question but thought it might be a good topic for discussion.
This is what I wrote a few moments ago.
"I am scrupulous, and have a prudential question regarding confession.
Currently I am in a dilemma regarding whether I should go to confession as soon as possible. There are a few factors in this: I have not received Communion for nine months, and I am afraid that it has been more than a year since my last grace-filled (valid?) Communion (objectively). I have become worried that, in order to fulfill the law of the Church requiring yearly Communion, I must go to Confession immediately and Communion afterwards (i.e. that would make my obligation to receive Communion immediate rather than merely within Eastertide). However, I am having extreme difficulty resolving in myself that I am sufficiently prepared to make a worthy Confession, as I am generally very cowardly, and I have committed sins in the past which were public, and would require public reparation, or at least the kind of sorrow which would include willingness not to do it again. I have had the opportunity for public reparation multiple times, and I have been too afraid to do it because it would be embarrassing or might seem surprising and incongruous.
There are scheduled confessions right now followed by Mass, and I feel that I am obliged to go.
However, there is also confession and Mass tomorrow morning, with a priest who has been my confessor three years in the past (though I have not seen him for several months), and I think it is more prudent for me to examine my conscience, write down my sins and pressing concerns, and go tomorrow. These were my plans, and my mother said I should just go tomorrow.
I might also mention that I am a student and have the additional obligation of doing my schoolwork (homeschooled) and that I have had internal tug of war over whether I should do my schoolwork or prepare and go to confession, and I know I need to obey my mother, but I also consider if I should ask my mother if I should go to confession. She thinks I should do my schoolwork and go to confession tomorrow.
I’ve heard somewhere that the virtue that the scrupulous need to develop is prudence (reason in practical matters). I can say from experience that this seems spot on.
For these reasons I tend to think that it is not a sin not to go to confession right now, but to have the intention to go as soon as I am reasonably prepared."