FWIW, I went to the secular, public version of your school and had the same experience.
I couldn't walk down the hallway without someone shoving me or punching me, just out of the blue, for no reason. I couldn't ride a bike to school, because they'd slash my tires. I couldn't have a plastic lunch box, because they'd smash it. And my 4th grade teacher, in particular, was vicious. She would say horrible things, and once cornered me and made me cry in front of the whole class, to their immense delight. (We'd just emigrated to Canada from the US.) I hated French for years after, because of her.
And I remember that feeling of salvation, when I won a bursary to attend a local private high school, where - hallelujah! - people were actually kind and civil to each other. Even the "bullies" there just ignored me, and then wondered why I wasn't bothered by that.
I also had a bit of a panic attack (short of breath, felt cold), the first time I had to walk into a school to register my eldest for kindergarten.
Far as I'm concerned, this kind of school bullying, whether by children or teachers, is child abuse. Just like any other kind of abuse, it leaves scars.
I pulled my daughter from Grade 3 and homeschooled her for a year and a half, because I heard that same note of frustration and dislike in her teacher's voice, that my teachers used to have, and it sent a chill down my spine.
I'm so sorry you had to go through that crap, too. It doesn't make you better. It makes you twitchy and hypersensitive and leaves sore spots that you can forget about most of the time, until something pokes you in one. And if my daughter's right about epigenetics (something she's been studying in university), my own wounds leave marks on my kids as well.
But, on the plus side, if you do have kids (now, or someday later), you can always try to make things different. Every child is one more chance to get things right. And I don't just mean your own kids. I tutor young children in reading and math, and any other subject they need. It feels like I'm fixing the past, in a small way, whenever I can make their present a little bit better.