It can be difficult to hide your SI. I wouldn't tell your class mates as that could be spread around and suddenly your the crazy emo girl, but what about your parents? Would they help you out or criticize you? For me self injury was a coping mechanism. A way to dull all the emotions I was feeling. I don't think it worked, it ultimately made me deal with more stuff, and now I have hundreds of scars. Thankfully they are on parts of my body that aren't normally visible, and I don't get looks from people.

I found a therapist to talk to when I was 18. She was helpful and taught me how to figure myself out and face what is bothering me. Do you think your parents would help you get into therapy to find better ways to cope?

I'm glad you have someone supportive in your life, your teacher friend sounds like he is there for you. I'm worried that he may not be able to help you. He can give you support and people find strength in that, but I think stopping self injury takes work, to look at oneself and evaluate how you handle emotions and react to situation and then make healthier decisions.

I don't mean to discourage you or make you feel bad. It is just something I struggled with for a while and how I got better. Therapy helped some, I worked on it, and I meet someone that I didn't want to hurt, by hurting myself. I hope things work out for you and be safe.