Help me from depressed kid.

Hi doctor, ibam single mother for 3yrs old. 6month bacj he got intro with hus father then he left not contact. My son used to attacher wih my dad. He need either me or my dad more comfort. Before my dad arrive he is quiet playful. After his grandpa arrived. Started shouting too energy very soundful. At same time he is showing too arrogant whatever he needy he do that time, if we said no then crying in louder manner. If we all go out. If i am disapper started crying., or his grandpa not at front started crying.. I really dont know how to handle him. All the time feeding he is avoiding., forceful or make him some fearful person identity ad feeding. If i am separate him from grandpa he will ok? Or get more depression,? Or i need to separate him. His grandpa doesn't handle him in good manner.. Help me for good solution