Did my father die angry, and how can I atone for making him angry? Will the donor be deprived of the merits of good deeds dedicated to the deceased father?

Abusing one's father is forbidden. However, your care for your father and your dutifulness towards him during his illness may be a cause for forgiveness. The father's anger is known to Allah, and sincere repentance erases the effect of sin, as stated in the Almighty's قول: "Your Lord is most knowing of what is within yourselves. If you should be righteous, then indeed He is ever Forgiving to those who frequently return [to Him]." Righteousness towards parents can be extended after their death through supplication and seeking forgiveness for them, giving charity on their behalf, maintaining ties of kinship through them, and honoring their friends. Dedicating the reward of good deeds to one's father brings recompense to the doer.