AITAH for ‘cutting off’ my dad

I (20F) am currently at university and recently in a conversation with my mum who has been divorced from my dad for a few years (he cheated) said that i need to make more of an effort to talk to him “because he’s my dad”.

For some backstory i didn’t stop talking to my dad because he cheated i stopped because he just isn’t a dad and he never tried to be one, he never turned up to anything whether it was a school play, a parents evening or any curricular activity and he is his own boss so work was not the excuse for missing out. He can’t remember the names of any of my friends or my boyfriend and refused to pay any child support to my mum when we moved out because he “had to pay for the dogs.” I feel like even though I am an adult now he still see’s me as an annoying 13 year old. All I wanted growing up was what my friends had, the loving supportive dad who showed up and comforted them when they needed it but instead i got a dad who’s never told me he loves me.

My sister (24F) has been talking to him and says that my dad just doesn’t understand how to be a dad because he lost his mum at such a young age and i need to make the effort for him. Of course i understand how hard losing his mum must’ve been for him but he’s had 24 years to grow and become a parent just like all his brothers did with their own children. Why am i the one who always has to make the effort to make plans and call him? I am not the parent i’m the child so i feel like i’m NTAH for choosing to separate myself from him?