Hi, my younger brother has autism and recently he's been getting increasingly violent. He's eleven, our parent's are divorced. Mum left about 5 years ago, so it's just me my Dad and brother. We do visit her, but really just for birthdays/Christmas, she lives quite far away.
Anyway, the other day Dad told my brother (no, he YELLED at him) never to answer the phone since it'll be someone selling things which, of course, he took very literally and now hangs up on everyone without letting them speak first. This is bad as I'm waiting on a job offer and last thing I want is him hanging up on them. While Dad was out I tried to calmly explain to him why he shouldn't do that but he must have gotten confused and it escalated into a meltdown with him punching, pulling my hair, yelling curses and pulling a kitchen knife on me. This is about the 3rd/4th time he's threatened me/Dad at knifepoint. I couldn't help it, I just started crying, I don't know what to do, how to communicate with him. He's already practically my height, and he hasn't even hit puberty yet, god knows what might happen when he's my age (I'm eighteen.) I just...idk, I need to get through to him somehow. Especially before I go off to Uni, Dad's even worse with him than I am, so when I'm off and away anything could happen, honestly I'm so worried. What should I do?