@Nanamiau

It sounds like you have seen a lot of terrible things.
It also sounds like you have a family that is dear to you and care about you.
There are terrible things out there on the internet.
You aren't doing those things, but I can imagine seeing those things can be very shocking.

There are things that our body or mind gravitate to that can be hard to control. Some find it in substances or accessible food.
Avoiding being in the situation where you can follow that temptation may be the only way to stop it.
You may want to look into filters on your internet browser to limit your ability to access content like that. There are lots of parental controls out there.