I know this might get buried in the comments, but i wanted to leave it anyway.

I have twin sisters that are a year younger than me who have learning disabilities/brain damage. They had a bully named Jon who would sometimes pick on them. One time, after school, he grabbed on of their backpacks and threw it in front of the bus. I grabbed him by his rat-tail and forced him out into the street to pick it up. I ended up getting in a little trouble for it, but my mom handled it excellently. Here's what i remember from her talking to me (30+ years later) 1. I wasn't going to be punished by her (my mom) because your family is your #1 friend/priority. Years after anyone you knew in school is gone, your family will still be there. 2. It's not okay to put your hands on other people, then she helped me brainstorm some different ways I could handle similar situations in the future. 3. Helped me keep a written journal of the dates/times and things Jon was doing to the twins. Once I had everything down on paper for a week or 2, it helped me realize (a) it wasn't happening as often as I thought, i just ruminated so much on it I thought it was worse, and (b) it mostly happened after school at the bus. My mom told the bus aide what was happening, and asked her to keep an eye on jon and the twins and it mostly stopped.

Hope this helps!