Is the feeling of losing the meaning of life, being preoccupied with daily routines, and the sense of impending death, an illusion or a reality, and how can one differentiate between the two and act accordingly?

Firstly: Piety towards Allah and diligent observance of dhikr (remembrance of Allah), prayers at their appointed times, and good deeds, because these instill vigor and tranquility. Abandoning them causes depression, distress, and the whispers of Satan, as evidenced by Allah’s saying: "And whoever turns away from My remembrance – indeed, he will have a difficult life." (Taha:124).

Secondly: The remembrance of death is praiseworthy if it motivates good deeds. Excessive fear of death is from the whispers of Satan.