I recently bought this book and it might be of help since it is explaining exactly the causes (and treatment) of negative self-talk.

Not sure whether I can post recommendations here (I'm not affiliated), but since it was already recommended here at HN and just in case you want to check it out, it's called "The Now Habit: A Strategic Program for Overcoming Procrastination and Enjoying Guilt-Free Play" by Neil A. Fiore, and it seems to have helped a lot of people.

Negative self-talk. Stop that. Thinking it reinforces it.

only if you choose to be.