How do you avoid getting depressed by increased knowledge of terrible things in the world?

I'm am 39 years old and up until 7-8 years ago I used to be quite a close-minded person who blamed immigrants, minorities and similar powerless people for the troubles in society. But since around 2016/2017 I've opened my mind up and gained a lot of knowledge about the super-rich and how they corrupt everything. And the more I learn about how psychopaths with deep pockets and too much power are willing to destroy everything and everyone for their own gain, the more I find myself losing hope in mankind and losing hope in general. So I'm really in need of some advice on how to handle an increased knowledge of terrible things in the world. How do you avoid feeling hopelessness in a world where 0.01% of humans are able to help the earth and mankind, but are unwilling to do it?