You do need to accept yourself as you are. If you do, then you won’t waste your time and energy on punishing yourself for having messed up at something, and you’ll be able to move on from the negative experience further.
Same with the World, the Planet. Yes, it can be, it is a nasty place, but it is what it is. It’s been fucked since the beginning and, really, it ain’t anyone’s or any system’s fault. If you can accept it as it is, and very likely will always be, then you and I can start tweaking it, improving it forward in small ways.
Of course, we are all, mostly, Pacifists, but what do you do if someone slaps you in the face, do you turn your face like Jesus, for another slap, and end up crucified, like Jesus did? Don’t ask, don’t expect Wars to end any time soon!