Does dereliction of duty and responsibilities towards others make money unlawful and lead to despair and negligence in prayer?

The solution for someone whose misfortunes have multiplied is to turn to Allah and obey Him. You have erred by despairing and abandoning prayer, which is the pillar of the religion. You must repent and maintain your prayers.

If your negligence in work leads to its disruption as an employee, then you are obliged to repent and perfect your work, and ill-gotten gains have their own rulings.

As for your shortcomings towards those around you, you must repent and seek their forgiveness, and be keen in the future to give everyone their due rights; your Lord has a right, your soul has a right, and your family has a right.