You may be one who watches the re-runs of the TV program "Gomer Pyle USMC." In that series, which was a "spin-off" of another TV program of that day, "Andy Griffith", every time Sargent Carter would prove Gomer wrong, Gomer, looking like an idiot, would exclaim a drawn out, "Well Golly!"
I think many Christians see themselves to be like Gomer while they see the Lord to be like Sargent Carter. If we think we have failed at a task for the Lord, we assume He will be disappointed in us, then we feel like an idiot and think, "Well Golly!" Don't you believe it!
God is never disappointed in you. That may seem strange, since you know that at least once or twice you parents were disappointed, then there was an incident at school where someone was disappointed in you, etc. But there is something that must precipitate the disappointment. That is, the one to be disappointed must have an expectation of not being disappointed. That means that one would be surprised it that disappointing event happened. This is complicated; right? Not really.....
Fact is, God already knew what you would do. Since He expected you to do it, the fact that you did it, didn't surprise Him. He loves you anyway in spite of your failure. That's another one of the great things about our precious Savior Jesus Christ! He loved us while we were still sinners so much that He died for us. So instead of feeling like a failure when you sin, claim the forgiveness Jesus is offering and leave sin behind.