Self harm, hearing negative voices

Is there any one else that randomly has a time where you spiral into a depression, and it's different than other times.
And what I mean by that, is having a voice in your head, perhaps like a subconscious of your own voice. That almost makes you feel like you lose control of your own mind and body, and makes you feel like you want to hit yourself, or cut yourself, or generally hurt yourself in some form. And that negative mindset, that voice in your head makes you want to do these things. Even if you have been working so hard to not self harm. Just suddenly, it seems like you want to, you have to.
It's really hard to explain.