Don’t spend time regretting your sin, repent from it right away. There is more to say.
Jesus said, “blessed are those who mourn” (Matthew 5:4), and this sorrow is over sin. There is a type of good conviction, a “godly grief” that is appropriate. But grief feelings are not the goal.
Paul wrote to the Corinthians:
I rejoice, not because you were grieved, but because you were grieved into repenting. For you felt a godly grief….For godly grief produces a repentance that leads to salvation without regret, whereas worldly grief produces death. (2 Corinthians 7:9-10)
If/when confronted, don’t try to pacify the other person with your coat of many bad feelings. Not only is this wishy-washy, it’s also not confession. It is also not gospel. This is like lowering your head and waiting for someone to hang a millstone around your neck.
Regret and sorrow and humiliation isn’t where we’re trying to get to. We hope to get out of all that by confessing our sin, to be comforted (Matthew 5:4), and then to turn away from it. Don’t just say that you regret something, resolve to stop doing it. You regret to be sitting in the mud puddle. No, brothers, get out of the puddle, or your britches will still be sopping and soiled. Puddleglum is an entertaining, even edifying, fictional character, but not a worthy epithet for Christians. You who believe are forgiven because Jesus died, and you can rejoice and obey because Jesus lives.