You can change that inner voice, either through meditation or quicker by one of these techniques https://www.amazon.com/Transforming-Negative-Self-Talk-Pract... . It's absolutely doable, just another skill, you can use your phone for reminders to work with some technique for one minute couple of times a day until it became habitual.

http://www.amazon.com/dp/039370789X by Steve Andreas. Not a book everyone needs, and it says the techniques don't work for everyone, but if you're plagued by internal attacks, getting them toned down and less common feels like a superpower.