To give you some perspective, watch a tribe of chimps in the wild grab a baby chimp from another tribe and tear its face off before proceeding to eat it. Nature is cruel and a lot of bad shit happens in this world. I used to think way too much about all the terrible things in the world too. Animal welfare concerned me too but I was more obsessed over rape, child molestation, genocide, etc. I wished I could be a superhero and kill all the sick fucks in the world. But of course I couldn't. And I only tortured myself with these thoughts. Not to mention this self induced torment doesn't actually help anybody. There isn't one less child who is molested thanks to me being angry about it. Neither does your obsessing over animal abuse result in one less cat in China tortured.
Here's a tip for happiness and a step closer to change: actually focus on the things you can change. Focus on actionable steps. Volunteer, donate, join a group that actually does stuff, act everyday with compassion, etc. The world is incredible complex as well so educate yourself. Real steps, not angry posting on social media to fool yourself into thinking you're doing something.