According to human nature and world thought, when we are failing, the right thing to do is condemn ourself and berate ourself mentally until we get better. We deserve to be punished, right?
But this isn't God's way. He know we're going to fail. He knows what we are made of. In Isaiah 40:6-8 God says, "All flesh is grass, and all its loveliness is like the flower of the field. The grass withers, the flower fades . . . But the word of our God stands forever."
That last part is very important. Since God's word will last forever, we can hold onto what it says about God and us. Romans 8:1 says, "There is therefore now no condemnation for those who are in Christ Jesus."
So, don't waste time condemning yourself (or others for that matter). When you do you are behaving and thinking in an ungodly, anti-God way.
And then there is the promise in 2 Corinthians 5:17: "anyone united with the Messiah gets a fresh start, is created new. The old life is gone; a new life burgeons! Look at it!"
And let's not forget the promise in Lementations 3:22-23: "The LORD's lovingkindnesses indeed never cease, For His compassions never fail. They are new every morning; Great is Thy faithfulness."
So, what have I become?
A new person in Jesus Christ. When I fail I get back up and start fresh letting that failure go.