Before going to confession, remind yourself of the immense mercy of God.
Italian priest Fr. Lorenzo Scupoli gives his powerful advice concerning sin in his spiritual classic The Spiritual Combat.
Scupoli writes, “When you feel yourself wounded from having weakly, or it may be even willfully and deliberately, fallen into some sin, be not over-fearful or over-anxious, but turn instantly to God.”
He continues by saying, “give thanks to [God], and love Him more than ever, wondering at the excess of His mercy, who, when you had so deeply offended Him, stretched out His right hand to save you from another fall … [then] commit yourself unreservedly to the merciful hands of God.”
When we sin most grievously against God, the devil will want to pull us into utter despair, doubting that God would ever forgive us. The good news is that God always forgives us and is waiting patiently for us to turn back to him.
Remember, God is a merciful God, not an overbearing tyrant ready to strike us when we sin. He is love and, as in the story of the Prodigal Son, is ready to strike up a feast when we have returned to the fold.