Why is my mother and brother like this?

My brother is 29 years old and my mom is so proud of him. He lives in the basement and never had a job and doesnt go to school. I have a job in my career and she always talks bad about me and is really upset she said because Im out and not like my brother. She tells people all the time that my son is so different and strange, she cannot understand whats wrong with me she says because I am different than what she wanted .. I dont know why she wants me to be loser. I even got a gf and she pulls a fit because Im dating her. She even told me dont expect me to go to the wedding.

Yesterday she took something from me and I caught her doing it I said do not take that from me. And she turns it around and says I was taking it from her and that I should not steal things. I get so confused with her. I try to give her respect but its so hard that she is always upset and wants her way.

Why does this all happen?