Had the Pope had an honest confessor, his penance would take up all his time and then some.
If the Pope ever came to me for confession, I would tell him:
“I cannot give you absolution because it was sinful to accept the Papacy, and it is sinful not to resign. You are the worst Pope in history, and I say that knowing there have been rapists and murderers among the Popes. You have done more harm to the Church than they did.”