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That is so awful and I am sorry nothing was done when you reported these incidents. It definitely doesn't have to do with what you were wearing. You were a child, what you're wearing shouldn't have mattered. It doesn't matter when you're an adult either because nobody deserves to be assaulted, but especially when you're a child. The important thing to remember is these incidents were absolutely NOT your fault and you are not a bad person for having experienced them. I'd limit contact with these people as much as possible and go no-contact when you can. If you still have to be around that teacher maybe you can ask to switch classes so you don't have to deal with him like that.