Is it normal that i mumble awful things to myself when i'm depressed/ashamed?

So, there have been times in my life where I've felt pretty down and full of regrets. And at the worst of times when I was feeling it keenly, I would often mumble terrible things quietly to myself, without even realizing it at first. They were usually awful mantras I'd repeat to myself until I realized I was doing it out loud, things like "You're going to hell, you're going to hell" or "Quit it, quit it" or "I want to die". Half the time it felt like it wasn't really me saying these things. I'm quiet enough that I don't think anyone's heard what I was saying, but there were a few times they saw me mumbling and thought it was strange.

Anyway, I'm fine now, so this doesn't happen to me except rarely at night when I'm on the verge of sleep. Has anyone else experienced something like this?