When you feel humiliated, empty, lacking all spiritual strength, when you fall and stumble, realize that a great light has been prepared for you. All of your imperfections and all the damage that you have caused—this-worldly, spiritual, things you did or didn't do throughout your life—all stand before you. Everything you ever did wrong testifies against you. You are stunned. You feel great anguish, and from the midst of that anguish you experience regret. Then you rise up and repent. You rise up from the depth of the abyss to the elevated pinnacle, from impurity to purity, from blackness to a great light.
As you emerge and rise, you have to pass through realms of darkness that overwhelm you and eclipse you. But be aware that "God is merciful and gracious," that "even though I walk through the valley of the shadow of death, I shall not fear evil, for God is with me." When you cry out to God from the midst of the confusions of the abyss, your voice will be heard. When you call out for the light of knowledge, it will shine on you. Wisdom and kindness will support you and crown you. You will swiftly return to the citadel, filled with wisdom, joy and strength.
Orot Hakodesh III, p. 252