God is not preoccupied with your past sins or failures.  He desires to see you put all that behind you by confession and, through repentance, live a new way.  So let your past failures go.  He is your Heavenly Parent, and He rejoices in your growth and character development. He cheers you from the sidelines and also helps you run the race.  God is for you, demonstrated by a love that will not let you go and a grace that keeps on giving.

“He has not dealt with us according to our sins, Nor rewarded us according to our iniquities. For as high as the heavens are above the earth, So great is His lovingkindness toward those who fear Him.  As far as the east is from the west, So far has He removed our transgressions from us.  Just as a father has compassion on his children, So the Lord has compassion on those who fear Him.  For He Himself knows our frame; He is mindful that we are but dust.” Psalm 103:10-14 (NASB)