Hi, I have issues with anger and rage too. I have wanted to hurt someone due to my anger but have been able to control myself. It sounds like you are controlling your desire to hurt someone by hurting yourself.
I have hurt myself too but not because of the desire to hurt someone but as a way to release the internal pain. It's like the pain is so intense that I can not hold another minute of it and it has be be released...this may be true of your anger.
I can tell you that I take Risperdal. Risperdal is an antiphycotic and is especially recommended for treatment of anger. I want to attend management class as it scares me to see how quick and intense my anger can come on and also because I am afraid I will hurtr someone...it is scary. The Risperdal does help.
However, you cannot get help unless you tell your doctor about your thoughts. Please seek help, it is out there. Jude.
Its good that you realize that it is destructive but the way you feel that if you don't hurt yourself you might potentially hurt another person is of concern. I would be concerned the thoughts might have some aspects of psychosis and it would be worthwhile to speak to your psychiatrist as soon as possible. There are also long term coping solutions such as cognitive behavioral therapy and for some people, dbt therapy in addition to medication and talk therapy.