I've recently learn they voice is our own to encourge. The more you give into it the more it seem to strike a coversation with you. Just got to relize your talking to yourself (which you know...it you so you should know yourself pretty well).
Even though I am having my own problem, I find when I hear that voice is to write down what it says, and then read it. This only sometimes works for me... and I recommend you do this next part outside. After you read it, you seem to notice it don't make sense, so burn it and say to yourself "That is no longer me... it is out of my system" I repeat, this only works sometimes for me.
It wouldn't hurt to try.