“Why are you cast down, O my soul, and why are you in turmoil within me? Hope in God; for I shall again praise him, my salvation and my God.”
From the verse I understand that the our soul feels the way we feel. Psalm 42 is about David longing for God after he committed sins. So every time we sin, our soul is also restless. And the only thing we can do is to come back to God as He the author of salvation.