I’m looking for books to read in your 20s but with a slight difference

Hi, there. I'm looking for books to read in your 20s. The slight difference is that, although I'm in my twenties, sometimes I feel that I'm older and I don't know why. I feel a litle bit tired of the routine and I don't understand because I'm just starting my life! So I'd like to read something like in order to understand how I feel and empathize with my feelings. If it is a novel, the better. Thanks for reading!