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.
Generalizations like “All X are Y” should be used VERY sparingly if ever, and are almost never correct or helpful when talking about large groups of people - i.e. an entire ethnicity. Jews are people like any other ethnicity, and as such span the whole range of ethics and personalities. I personally know a very ethical and kind Jew who does not deserve to be labelled as an asshole or anything similar, and I know of many more who also prove that claim wrong.
Moreover, being abused is not a valid excuse to be an abuser. A lawyer tells a story about his client who tried to justify his domestic violence by saying he was abused as a child. The judge responded to the effect of, “then you should know even more than most people how very destructive and wrong it is”.