Very similar to my own, as you mentioned being positive and confident helps tremendously. On the bright side I've read nearly every truly gifted mind has had some type of voice in their head. So we are in good company.

Difference with mine is I have one voice that mimics other voices and environmental sounds. He is mostly outside of my head, but at times can talk within so too speak, he can even make it echo through my head when he is strong. He doesn't say much and he is always there, like yours, however mine does seem to rest at night to some extent. Once I get to the point he is not as strong I start doing audio exercises. Focusing on a constant sound from my environment and trying to add in other sounds to make it more habitual for me to fall back into the sounds of my environment instead the voice in my head.