I am so, so very sorry that you are being tormented at school and not supported at home. Sadly, not every kid gets the parent she deserves. You aren’t getting the love and the protection you need. You are not wrong to be angry and sad about it. But I’m sorry to say that you can’t make people love you who have big problems with loving. I wrote an article for kids like you that you might find helpful. Click here to read it.
When parents aren’t able to do what they should, it’s important to find other adults who care. You already have a teacher who is concerned. If you are too shy to talk to her directly, you could give her a copy of your letter and this response. She won’t be able to make your parents do what they should but she may be able to help you sort things out at school. If she can help you feel safe in school, you’ll have at least one place where you can grow into the mature and competent person you are meant to be.
I wish you well.