Why do you feel that you can't do anything?

There are two reasons. One is that you study too much, which leads to your numbness and mindset. At this time, you should go out for a walk and exercise more. Second, you have learned a lot and feel that your knowledge is too narrow. Too many questions make you feel that you know less. As people grow up, they need more abilities. You can't keep up with what you want. I feel the same way. I wish you progress in your study.