I also talk myself a lot, in my case it is worst cause there are periods of my life that my thinking is very negative and exaggerated. To fight this I also tell myself "not to trust in those negative thoughts" therefore I end up overwhelmed by my fears.
I also use to think that, being lonely, and talk to myself will drive me nuts, but that's another FEAR, hahaha I can't believe it. As you guys said, normal people also talks to themselves, some psychologist even recommend it. But me, the negative thinker, would think that, talk to yourself is a signal of getting crazy.
That's why it is important to have a strong supportive circle, like friends and family. Sadly I've been avoiding them for too long. But there is still hope, I joined SA meetups, I'm talking with my therapist, and just by talking I find out that many worries are bullshit.
We tend to think negatively TOO MUCH.