There's 2 different issues here - preventing cruelty and all kinds of horrible things which happen, from occurring in the future, and the Op dealing with the horrible images which are now in her mind.
I think that the Op is more interested in the second issue right now. That's not to say that the first isn't important, but her concern that the moment is about herself and her mind, and I think it's okay for her to come on here and ask for advice about that. Campaigning etc might be one way to deal with what is in her mind, but actually might make her think about it more and actually she needs to get it out of her mind. In some ways this might seem selfish and to be ignoring the issue, but I think it is valid.
In this world there are so many terrible things going on. We know about some and not all. I'd say that we cannot campaign about all of them. I think we need to each choose areas where we feel strongly and make efforts in that area - that doesn't mean totally ignoring other issues, but recognising we cannot change absolutely everything. And yes, we have a duty to inform ourselves about what is going on, but that's not the same as damaging our minds with images of atrocities, or if we have seen them by accident, by fixing them into our minds permanantly by focusing more in the issues, if that is problematic for us.
It reminds me again of the the need to protect our minds. We can't unsee things. It's one of the reasons I don't watch 18 films. People often laugh at me, but I just find I don't need to see the sex and violence which plays on my mind. Op, if it's upsetting you and campaigning about it doesn't seem right for you, then try to move on....possibly come off this thread if it's reminding you about it. Watch something else,mead something else, listen to some music. The images will fade and come to you less frequently but it might take a while. Sorry this happened.