The Dialog with Myself

I've already written that what I want to change in myself. Surely it's not easily to change myself (at least for me). And I think that to put off bad habit may I need to have split personality in some way. And one of that personalities must say "That is bad, don't do it" when it is needed. May be this should be something like fight between good and evil, though I'm not sured that someone in me is really good or evil. May be both of them should help each other. There must be a dialog inside of person, dialog with himself. But how to speak with myself? The most obvious way for is to have to "Me's". May be this a psycho disease? But to learn on fault your need to have someone who will point on them, and nobody as you can now what you do and why you do.