What is the way to restore intelligence and strengthen faith after practicing masturbation and feeling a decline in concentration and a deterioration in one's psychological state?

Undoubtedly, sins have negative effects such as alienation of the heart, difficulty in affairs, darkness of the heart, and engendering one another. The purpose of mentioning these effects is not to induce despair, but rather they should be a motivation for repentance and fleeing to Allah. One must strive to lower the gaze, maintain the prescribed remembrances (adhkar), frequently engage in remembrance of Allah and seeking forgiveness, and follow a healthy lifestyle. If a slip occurs, one must repent immediately and not delay it, for Allah accepts repentance and forgives misdeeds.