Have you every been close to doing something wrong, to breaking a precept but, fortunately, found you were unwilling to do so? I have, time and again, and despite the fact that I could see the occasion as a chance to take joy in the power of my sila, the very fact that I arranged circumstances to bring me to that point leaves me wracked with guilt. Let me be clear: no precepts were broken but I could have made better decisions that would have kept me from enduring into any questionable situations.
But, as we all know, there is never an end to “shoulds” or “woulds” so what is left is to AFL it. Acknowledge that it was unskillful, forgive myself completely and learn how not to do it again.
I have to give Ajahn Brahm credit as the source for this handy abbreviated version of self-directed brahmavihara practice and would stiffest that anyone unfamiliar look him up and listened to some Dhamma talks.