There is no big or little sin. Sin is inclusive. But so is God's faithfulness to those who are His and confesses their sin. He forgives and cleanses from ALL unrighteousness" (1 John 1:9). What an awesome promise! So, don't condemn yourself (Romans 8:1), go to our Advocate and Intercessor, Jesus Christ. Not sure what to say? Check out David's example in Psalm 51.