Really, attempting to ‘catch a priest’ minutes before they are scheduled to celebrate the Holy Sacrifice of the Mass to hear a confession is really impractical -and your certainty that you are the only one is non-sensical … you may be but there are several hundreds of people attending any one of the 7 Christmas Masses at my parish … the priest has many people to address at that time - as important as hearing a confession is and it is important - that is not the appropriate time or place. If you had concerns regarding your worthiness to receive - you should have participated at Mass and refrained from receiving … It is not necessary to receive at every Mass and actually per Canon Law - you are to receive at least once a year during the Easter Season - it is necessary to participate in and attend Sundays and Holy Days of Obligation. It is not possible for a priest to be immediately accessible for every person who feels the need to go to confession on their personal whim … and by your own testimony here - you could have approached the day before but did not.
This comment in and of itself speaks volumes … scrupulosity

- the need for a spiritual advisor :yup:, the ability to understand/discern the difference between mortal and venial sins
Yet yourself clearly stated that you* should have* looked for the priest the day before and
could have but*** failed to do so!*** … something that you felt was so very important - perhaps
mortally so - yet you - the person responsible for the sin failed to act immediately and you now castigate the priest for not acting fast enough - with the immediacy you wanted …
Perhaps it is your attitude that is grudging …
Pssst: in reality - you do not reveal your sins to the priest but to Christ - the priest is acting in Persona Christi - it is Christ that hears your sins and Christ who forgives …