<human>: Can you give me the gist of the text in a nutshell?

I have the most wonderful life.  An amazing SO that I live with, two rescue fur babies, and a wonderful job at a start up.  My brother has a great job, lives with my mom and has a girl he is dating that often stays at my mom's house as well.  My mom caters to my brother's every need.  She shops, cooks, cleans, does laundry and even lets him sleep in her room.  My brother isn't a bad man, but he is certainly the result of being overly catered to.  When we were younger, we would both fight as normal.  Now that he is in his mid- twenties its intolerable and dangerous.  I have tried to explain my feelings, be reasonable, etc. But he always resorts to violence when angry.

I have threatened to call the police many times, but my mom would get mad at me for even thinking about it.  He has locked me in a closet and thrown nails at my face for not wanting to help him with a project, thrown me into a wall for being in his way and even twisted/bruised  my arm for refusing to move my laptop charger.  My mom always sides with him, stating that if I wasn't so difficult, he wouldn't get that way.  I think it is worth noting that my father was also abusive to her and us.  

I have a life of my own now and am unbelievably happy.  For the first time in my life, I feel respected, truly loved and appreciated.  That said, going home to see my mom and brother is hell.  He tells me that I am ugly, stupid, vain, etc. along with the physical violence.  He has even punched me for being too affectionate with my SO.  Because my mom sides with him, I am at my wits end.  Do I have to cut them both out of my life to be happy/sane?
<bot>: My brother resorts to physical violence when angered.  My mom enables him and I fear I have to leave them both to continue to be happy/healthy.