Autism & Broken Trust with older siblings

Anyone else have a sister that is a covert narcissist? My older sister(normal) has always verbally and emotionally abused me. She also ignores me all the time. Occasionally she will tell Hi when she comes to visit but most of the time she just acts like I don’t exist. 

I’m moderately to severally autistic, and I’ve never been able to have her support as a caring sibling. She recently tried to have me committed into a mental hospital but that failed because I was cleared and declared mentally sane just very autistic and intellectualy disabled. It was also declared that I am NO threat to anyone or anything and am NOT DANGEROUS For any reason. They said I am a very joyful autistic who just really loves her animals and that I was a delight to talk to. 

So, I don’t trust my sister anymore and can’t be around her. She told my mom that as long as I am around that she won’t come visit. It’s very sad and confusing because my meltdowns are never violent all I do is cry and talk loud. But according to my sister I’m very violent, unhappy and have the potential to murder….. like um what?!? Why would she make this all up? 

anyway does anyone else have a normal sibling they never see or talk to anymore? Is it okay for me to never have a relationship with her?