Why are we so hard on ourselves?

I don't expect other people to be perfect. Other people don't expect me to be perfect. Hell, I don't even expect myself to be perfect. But I beat myself up over every single thing that I see wrong with me or every tiny mistake I make.

Last weekend I did a load of laundry and I realized after an hour that I had accidentally chosen a 95°C programme instead of 40°C. Of course anyone would be annoyed if they had ruined all of their clothes, but I was flooded by an intense self hate. That's not normal, is it? (And in the end, it turned out my clothes were all fine, nothing ruined.)

I want to cry every time I look in the mirror because I am overweight. I'm disgusted with my own body. Yet other people with the same figure as me - I don't judge them negatively for it.

My rational mind knows it makes absolutely no sense.
I never considered hurting myself phyiscally. Never self harmed and even in the deepest depression I still took care of myself. Maybe I didn't eat the healthiest things, but I ate, I still showered, I tried to get out of the house....
So why would I hurt myself mentally?
But knowing this, instead of helping, only makes me beat myself up more. I know what I am doing is harmful to myself, but I keep doing it so I must be extremely stupid.

Hoping writing it down like this will be a step in the right direction.......

The Skeezyks sends his best wishes with the hope that what you have written here does indeed become a step in the right direction.