I recently heard Phil Ryken talking about preaching. He told a group of ministers that as long as he had been faithful, he didn’t spend a lot of time worrying about whether or not it subjectively felt like his sermon had gone well.
He pointed to the Westminster Larger Catechism, question 55:
Q: How does Christ make intercession?
A: Christ makes intercession, by his appearing in our nature continually before the Father in heaven, in the merit of his obedience and sacrifice on earth, declaring his will to have it applied to all believers; Answering all accusations against them, and procuring for them quiet of conscience, notwithstanding daily failings, access with boldness to the throne of grace, and acceptance of their persons and services.
That is good news and freedom for preachers. It means that because of Jesus, even your C- sermon is counted as an accepted service before the throne of grace!