Worst day ever WWYD

This is a vent, it doesn’t let me respond to people when I tag it as a vent. My NK 6, had a complete and utter meltdown today. He was smacking and hitting his brothers, so I told him I was calling his parents. He broke DOWN and began smacking me and trying to take my phone, I had to put my hand out in front of me to separate the two of us because he wouldn’t stop hitting me. I went into NP room JUST so i could call them and he wouldn’t stop screaming and trying to open the door. I tried to locked it so I could call the gc I am in with NPs, they wouldn’t answer so I texted “I need someone to please call me” This was maybe 2 minutes of me in the room MAX and the door didn’t even fully lock. MB came home early and was mad, she seemed to be mostly mad at NK but I could tell she was angry with me as well. We went to have a conversation and she let me know we would be implementing a new strike system for next time. What upsets me is her response to my response, I know that wasn’t the best decision for me to make…I don’t have children and 3 is the most i’ve ever taken care of at once, so I had no clue what to do in that moment. I felt as though separating myself from the situation and leaving him in the living room where there are cameras, was the best decision but now that I’m level headed I know that wasn’t the smartest decision for me to make. MB came to me and told me I shouldn’t have done that, “what if he decided to take his anger out on his brothers” was her reasoning, he was attacking me in the moment. I don’t want him to take his anger out on his brothers but he wasn’t going to turn around and attack them, also why do I have to put myself in the line of fire to get hit?? I feel so burnt out and it just felt like the solution was “let him hit you while you lock him in a room instead of locking yourself in the room”

Edit: She spanks them, I did not realize there was a difference in severity between the two words…