Having been there, I can say that it make take time to forgive. It certainly took me many years before I could start that process. You don’t have to forgive them now. Focus on your own struggles, and finding ways to deal with them. Personally I think you shouldn’t waste energy on people who do things wrong. Way too many everywhere.
If you truly do want to understand, try to consider the job of the Mechanech. They are responsible for so many, and there isn’t a single right way. Every child is different, every situation is different. Children don’t come with instructions. Many will simply apply general rules to everything. While this works for many, it also destroys the ones who are left. One important thing I have learned through life, is very rarely are people evil on purpose. Most probably they assume that somehow this will help you. Sounds crazy, but that’s what happened to me. From my point of view, I tried extremely hard to do everything right, yet every teacher would comment at the least, or bordered on abuse for what they perceived to be my lack of effort. Now I am in a different place in life, I can understand what happened. I saw my struggles. I didn’t see what my teachers all saw. A bright student who constantly slept in class, looked bored, and rarely did homework, or studied for tests. I really did seem disinterested. Today, I can see there was a 3rd factor that was at work. A home factor that wasn’t visible to anyone, even me at the time. So what my teachers thought would encourage me, tore an already battered child. I’m not sure if I have fully forgiven everyone, but I’m on the road. What has helped me heal, is knowing that I can do something about it. I can’t change my past, but I can talk about it, bring awareness to these issues, and maybe things will change soon.