How do you get yourself to not say cruel things to yourself constantly?

This sounds laughable. A lot of ppl would laugh at this and I get it. But this is a real thing. How do I stop myself from beating myself up every time I make a mistake. Every chess game, “pathetic you didn’t see that tactic”, every time I read something and don’t learn “you’re an idiot. No wonder your education has lead you nowhere.”

It’s self fulfilling.

Thing is I never talk to others like this, even those who are rude or mean to me, because somehow I can see them as being deserving of ying yang crap but not myself.

I kind of fit the “nice guy incel” type, but I don’t blame others for my loneliness. Lacking connections fuels the self cruelty more. The worse things I can say to myself, the less a bully can you know?

How do I get out of this? Like this will ruin my life if I don’t fix it. This is bad and honestly, when I get sympathy from therapists I feel as bad if not worse. I can never relax, even with time off work. I have intense rage and have had problems stem from reactions. You can laugh or say I’m pathetic, trust me, you didn’t beat me to the punch of anything you can come up with.

Idk maybe I’m a covert narcissist or something like that. I’m impulsive too and have done some stupid things but I’m not a violent or sexual offender. Why do I feel like I’ve been given the fucking death penalty (hyperbolic but not that much)?