Firstly, you honestly sound quite self-absorbed and rude. We only get one true family, and I think you should try to feel more grateful that you’re able to spend time with yours regularly. I would love to be able to see my dear family at reunions more often. Sure, you might be an introvert, but that doesn’t mean you can just ditch your family because you don’t feel like interacting. Books and music will always be here. Appreciate your family while they’re still around.
Yes. sometimes little cousins can be very annoying, but they will outgrow that behaviour. When you’re all older, you might find that these cousins end up being your closest friends. Also, the family members you want to turn your back on now will probably be the people you need later on in your life during difficult times.
If you really can’t stand being around your own family, then just don’t go to the reunions. Make up excuses and don’t go. Simple.