Serious answer: I remind myself it’s normal to be shocked by some stuff people do/create. I check the content against my ethics, and try to decide if I’m being uptight or if it really is messed up. If it’s something that isn’t unethical/harmful but I just don’t like, then I remind myself that not everyone needs to share my tastes.
If it’s genuinely terrible I allow myself to feel the anger/sorrow for a bit, try not to let it become excessive, and congratulate myself on having limits that fit my ethics. I remind myself that good people exist and they are the ones I want to support, emulate, and engage with. As others have mentioned, distraction can also help. Video games, music, socializing - whatever will move your train of thought along.