These words come from the introduction to Rebbe Nachman of Breslov's Tikkun Haklali prayer:
"And now, how can I possible rectify this, and how should a lad like me merit to correct that which I have blemished? Despite this, I know, and I believe in perfect faith that there is not despair in the world at all. And still I have hope, my hope has not faded for HaShem's kindnesses have not been tempered, for His mercy has not ceased."
Ki Lo Chalu Rachamav- For His Mercy has not ceased!