My brother was being abusive. I am shaken up.

I took my brother out for his birthday yesterday, paid for his drinks ( he was drinking heavily, I don't drink alcohol) . The day started out ok, but then he started shouting and screaming  at me at the end of the night, grabbed me, kept flicking his hand on my coat even when I told him to stop it and said that I am killing our parents off and kept putting me down because of my autism. I was hysterical in tears last night, kept shaking, was yelling out in fear when I was in bed, and I am still shaken up today. He has never treated me like that before. I don't know what to do. I am also very upset and confused over feelings that I have over a friend of mine who also has autism. It's too much.