Who can tell me how to live actively and what's the fun of living?

First, you have to decide what you like. Do what you like and don't be overwhelmed by society. I believe you are a capable person. Don't you dare to give us a platform to express your opinions here, which shows that you have a lot of information. Let's go on. Venting is the best tool. I suggest you don't always think about sad and uncomfortable things. Happiness is a weight to relieve stress. Living is a pleasure in itself.

Lots of hobbies. Mountaineering, singing, dancing and playing ball are all good ways. In short, you should live a good life and live a wonderful life. Life is rare, don't be mediocre. I will always support you. Do what you want, except ruin your future.