What is the way to repentance, guidance, and returning to Allah after feeling that one's salary is unlawful, and there is negligence and failure to master one's work, and accumulation of mistakes, and deterioration of health, and public exposure of one's affairs?

You must repent sincerely for your shortcomings at work and rid yourself of any unlawful money you possess by returning it to your employer. Look to your future with positivity and optimism, and do not dwell on the past so that despair does not afflict you. Be keen on what benefits you, seek Allah's help, and do not despair. If something befalls you, say: "It is the decree of Allah, and what He wills, He does." Do not be concerned with your colleagues knowing about your situation.