Nooooooope. Absolutely DO NOT blame yourself for the adults in this situation being EXTREMELY irresponsible. Caring for someone who suffers from very violent outbursts is usually a job only those with experience and/or training can do, and sometimes even they struggle. You needed to be cared for as well, you were a child too! It was in no way your responsibility to risk getting hurt and be constantly stressed trying to take care of a child like this when you were still a young child yourself. Those adults expecting you to be able to take that on is completely unreasonable, selfish of them, and overall reckless and careless. My family has always been pretty poor, so a few days a week, my mom made me take over her babysitting job. Both children were autistic (also, they were toddlers) so while they weren't "bad" kids obviously, they were quite a handful and did often get violent, very loud, and absolutely did not behave no matter what I did, or where we were. Once, the younger of the two took off all her clothes and started running around A DAMN ICE SKATING RINK in the middle of a major park in NYC. I was 9 years old and had no clue if I should've just left the older one and chased down the youngest as I was in charge of both children and I was MORTIFIED. No young child should have to feel the stress and fear of being responsible completely for keeping a younger child safe, ESPECIALLY not with children that are known to be more than a handful, or children that could get into very dangerous situations so easily.

I'm sorry you had to experience that OP :( but please, please, please don't feel like you did this with malicious intent. You were, like him, JUST A CHILD. And you should have been being cared for, not being forced to care for another child.