I can't tell you how many times I've prayed Psalm 51. I've prayed it more than any other psalm.
It's both a blessing and a curse to have a sensitive conscience. A blessing because it is morally wholesome to be attuned to your failures, especially how you treat others. I think guilt and shame are salutary emotions, necessary, healthy and vital aspects of being a good human being. We need these emotional nudges to prompt social repair and to make amends.
And yet, it's also a curse to have a sensitive conscience. There's the constant temptation of scrupulosity. Shame and guilt can tip into mental illness.
What I can share about my own journey with a sensitive conscience is that Psalm 51 has been my constant companion. I've turned to it again and again when I've experienced moral failures. "Create in me a clean heart, O God. Renew a steadfast spirit within me. Wash me, and I will be whiter than snow. Blot out all my iniquities."
I have prayed these words so, so many times. They have carried me and have been my companion through many dark hours.