Why do I not feel sad about my father's death, and what is the reason for my hatred of school after his death?

It is recommended to attach oneself to God alone and to rely upon Him, for He is the Arranger, the Provider, and He is the successor over the family in the absence of the father. Everyone is in need of God's grace. Ibn Qudamah recommended that he who is in his home, among his family and wealth, is no less in need of God's grace than he who is in the sea on a plank. It is also warned that showing grief and weeping over the deceased, which is permissible, should not exceed three days.