Why do people treat autistic people differently thank non autistic people?

I mean we’re people like anybody else. I’ve always been treated differently than my siblings and cousins by family even though they love me. Some relatives aren’t fond of me at all. I get treated like a baby and they don’t think I can do things for myself and people are more harder and more harsher on me than anyone else. I’m the punching bag of the family and when someone happens people take that shit out on me and me only. It’s so stressful and I get pressured to help because I’m the “nice girl” that is expected to help. People get in my face when they talk to me and trick me out of my comfort zone.