My sister hates me and so my parents won’t let me come over when she’s there, how do I stop having to miss out because of her?

I can’t come with the families there, I don’t mean my sister and parents but I mean the others in the family. This really hurts me is there a time that I’d like to be with family and see family but I can’t if my sister is there and she’s there all the time. What do I do? Next week my aunts and cousins are in town and they’re gonna stop by but I won’t be welcomed because my sister is there. My father told me when I offered to apologize to my sister that I should not because I did nothing wrong. My sister has a long history of bullying me because I’m different due to learning disabilities.  

What do I do? My mother wouldn’t even let me come in for more than a minute when my brother was in town last fall because she didn’t want to set my sister off. My sister is a narcissist.