how to deal with a narcissistic parent?

my father is a narcissist and he doesn’t understand why his actions end up hurting my sister and i. he kept a huge secret from us for 6 months that he had another family and then just told us out of nowhere and expected us to not be mad. he also once, out of nowhere, gave all of my pets away bc he didn’t want them anymore. and he didn’t even understand why i was upset. he constantly does things like this and he puts me in bad situations like how he had a girlfriend for 3 years, and she was like a mother figure to me. i had more of a relationship with her than my dad. then out of nowhere my dad broke up with her and told me i wasn’t allowed to see her or talk to her anymore. it just makes me mad how he doesn’t get how his actions affect me.