I easily stop negative self-talk with positive thoughts

The voice that does it is usually not talking in the first person. It says you. You idiot. You always do this.

Which is strange, if it is supposed to be you speaking. Voices that address you as you generally came from somewhere. A teacher. A parent on a bad night. Somebody from a job you left in 2011. It got absorbed and kept running long after the person stopped saying it.

Recognising the accent is most of the work. It is much harder to be flattened by something once you can hear whose delivery it is borrowing.