what do I do? in Help

I am trying to stay positive about life but it is hard. I am so stressed out about my brother he is just so selfish. yesterday he treated his teachers like crap but won't reflect on it . It is not the first time. This morning my mom found out that yesterday he didn't just treat his teachers badly and she asked him if he cared to explain. He said no and then got upset because my mom said he cant go to his chorus concert. He banged on the table and caused a ruckus.  When my Dad asked him about what the noise was and why he was banging on the table he ignored him and said " I don't want to talk about it" and it went on and then my brother stormed out of the house. I should be used to my brothers crap like I have lived with him getting the police called on him because of his violent tendencies when he gets stressed but it has put such a toll on my mentally health for years. Please help . What do I do ?