I used to have a horrible, constant inner critic, mirroring mainly all the negative comments from childhood.
I had some therapy, started innerly sticking up for myself as if the 'critic' were saying those things to a best friend or little sister.
Innerly shouted "No!" a lot, or "how dare you! Go away!"
Somewhere along the line it did completely go away. My head is silent now, or filled with drifting random music - I find myself constantly absent-mindedly humming along. I also reverse-aged about 10 years!
I self-reflect at set sessions now (meditation), and my mind becomes like an inner conference - hearing lots of different opinions and insights. Abuse is not tolerated.
It's a much more tranquil life, and for anyone who still has an inner critic, I say unreservedly LTB!