Why do I hate family gatherings so much? I feel particularly uncomfortable every time and don't know what to say.

This is also normal, because you don't think that you are really together because of family ties. This is just a show, a party to save face. Most parties are like this now, so don't pay special attention. I ate a meal in a daze. As for what they say, it can be completely shielded, and it is not worth wasting time thinking. If you have a clever reason, you can not attend such a relatives' party, because it is really boring. Why not spend your time on other more meaningful things? That's it, so relax. Most of them do. Times have changed, and China's relatives have completely disintegrated and become snobbish.