I used to have thoughts similar but since I have been therapy I have found that if I ask the voice/thought, Why do you want to hurt me? What did I do to upset you? Is there something you are trying to tell me? Usually one of those questions will evoke an answer/thought and bring us into a dialogue. I think a lot of times when I was thinking about hitting myself it was because my alter was trying to communicate it's displeasure with something I did or didn't do. Once he or she was able to get the thought out he/she had less desire to hit me. Just ask him/her what they want. I hope that helps. Feel better