It sounds pretty gruesome but I think it's actually a positive dream; the fact that you managed to kill the stalker is good... I don't know what's happening in your life right now but the dream/stalker is likely to be connected to something that is hanging over you, something worrying you, or something you are doing that you want to stop doing; you faced the thing and killed it, which is a very positive thing to do with your fears inside dreams; I think it shows that you have the will and the ability to overcome whatever it is the dream represents in waking life... hope that makes some sense?