Why?

So today I found out that my art teacher told the current AP and portfolio students the scores that we (myself and the other AP students of last year got and why we got them so that this year's class wouldn't repeat our mistakes). He never asked for our permission to tell other people out grades, and he used some of my pieces (and others' I'm sure) as examples in his PowerPoints.
what the fuck?
I had my teacher since freshman year, so he was with me every day throughout high school. He was like family to me, I loved him so much
when I got my score last summer I emailed him about my grade and told him how upset I was. I though it was in confidence, but I guess not. 
I am so hurt right now I don't even know what to do. I can't imagine anyone would do something like that
I just see the classroom and him talking and everybody listening to how fucked up I am. It makes me want to die. He was my favorite teacher, I respected him so much, and I thought he actually cared. He knew how depressed I was/am, especially because of things happening with my family
and then he goes behind my back like that? I am so humiliated and ashamed, I can't show my face around the school now. I can't walk into a room knowing that I was discussed in such a way, it's so embarrassing and painful
Im so hurt and devastated right now, I don't even know what to do
part of me wants to email him and ask him why he would do something like this, but I don't even know what to say. "Why do you hate me too?" "How would you like it if someone did that to you?" I can barely believe this is happening. I tried to kill myself last year, between school and home. I was made fun of my entire portfolio year, people would cut up or step on my pieces, people would hold them up and talk about how it wasn't 'real art' or how badly draw it was. But after being bullied since kindergarten, I've come to expect things like that from my peers. I never expected the person who would hurt me the most would be my favorite teacher.
then it just brings me back to the horrible things my English teacher said to me, but at least he said it to my face. Between my English teacher and my art teacher, I just want to die
whats so wrong with me, what is so fucked up that everyone does this to me, just like my family?
I haven't stopped throwing up since this morning, so I'm probably going to be at the doctors the rest of the day. But I honest just wish I would die
its obvious everyone would be better off without a piece of shit like me around