I think I may understand why you are cutting. A large part of it likely stems from the fact that fundamentally you are having feelings of worthlessness. I do not think it is a coincidence that you cut when you are having very negative thoughts about yourself.
Another reason you may cut is because you believe that you deserve to suffer. You did write that you “hate yourself” and that you “ruin the life of others.” It also seems like you don’t know other ways to deal with your emotions. That may be another reason why you cut.
Some individuals who cut say they do it because they can’t feel, almost as though they are emotionally numb. They are disassociated from their emotions (i.e. feel nothing) and the only way to feel anything is to cut themselves. When they do cut they feel pain and feeling something is better than feeling nothing. They describe it as a release.
Perhaps the aforementioned reasons explain why you harm yourself but more importantly is how to stop this behavior. You say that you can’t stop but please know that you can. I have known many adolescents who were eventually able to stop. Usually they stopped when they came to believe that they don’t deserve it and were taught alternative ways to deal with their emotions.
It is also important to understand that you do not deserve to suffer. As I discussed above, part of why you self-harm may be connected to your belief that you deserve punishment. You don’t deserve it. That is the type of thinking that allows you to hurt yourself and it has to change. I believe that if you were able to enter counseling you would learn to change your thinking and eventually your behavior.
You also should know that there are better ways to deal with your emotions. I would recommend that you make it a point to speak to someone when you are feeling upset. You said that your mother would be upset if she learned that you were cutting. You don’t necessarily have to tell her that you were cutting but you could go to her and have a discussion about what’s bothering you. If not your mother, then go to a friend, a mentor, a school counselor or someone you trust. You need to reach out for help.
Asking for advice and talking about what’s bothering you are two ways to deal with this problem. You may also want to consider keeping a journal. Writing about your feelings may be a healthy outlet and could serve to defuse your strong emotions. You may be less likely to cut yourself. Other ideas include exercise, engaging in stretching or relaxation exercises, taking a yoga class, and so forth. Those are also ways to defuse your emotions.
The ideas listed above may be beneficial to you but I would strongly suggest counseling. I recognize that when someone is cutting they are suffering tremendously. It is a sign that the individual needs help. Cutting is dangerous and you could accidentally harm yourself more than you intended. That is why it is important to consider counseling.
I am encouraged that you wrote a letter about how you’re feeling. The next step is to ask your parents if they will take you to a therapist. I believe it is the best way to handle this situation. Counselors are trained to deal with the issues that you are facing. If you don’t want to ask your parents then go to the school counselor and he or she can help you either within the school or refer you to an outpatient therapist. Thank you for your question and I hope that you’re able to find help. Please write back if you have any additional questions.