All perfect praise be to Allah, The Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad is His slave and Messenger.
Your father has no right to prevent you from visiting your mother; preventing you is urging you to sever the ties of kinship, while Allah says (what means): {And cooperate in righteousness and piety, but do not cooperate in sin and aggression.} [Quran 5:2]
You should not obey him in this as there is no obedience to any person in the disobedience of Allah. ‘Ali, may Allah be pleased with him, narrated that the Prophet said, “There is no obedience [to anyone] in disobeying Allah; obedience is only in what is permissible.” [Al-Bukhari and Muslim]
For more benefit, please refer to fatwa 84942.
He has no right to become angry at you or refuse to pardon you, because by just visiting your mother without his permission, you are not being negligent of his rights.
Also, he is wrong in disowning you or refraining to see you. We advice you to be patient with him and to supplicate Allah to make him regain his senses and strive to please him even by seeking the mediation of righteous people. We also advise you to endeavor to reconcile between your father and your mother and try to convince him to take her back if this is not the third divorce, because if he divorced her thrice, then she is irrevocably divorced from him with major separation and he cannot take her back (unless she, after having married and established conjugal relations with her new husband, is divorced for some reason or widowed).
For more benefit on how to reconcile between disputing parents, please refer to fatwa 95504.
Allah knows best.