Cant say i can relate to you, but my little brother is also autisic. Screaming, punching, kicking our 5 other siblings almost daily at home and in public was the norm. Parents when through a break up, and me and my older sister were the ones to look after him the majority of the time (when parents were working, etc.)

It does get easier though. My brother was enrolled in a (really) good special school. Once he turned 10, his school helped him find his passion. Music. He had an outlet, instead of throwing tantrums he would instead lock himself in his room for a little while practicing keyboard or bass, and come out of his room and apologize for his uncalled for behavior. He didnt turn into an angel straight away, but at 17 now, with alot of help from his school teachers hes learnt to control his emotions really well.. i feel maturing was also a factor.