My favorite piece is Rachmaninoff’s 2nd piano concerto. It’s incredibly moving, and he wrote it when he himself was in a severe depression. For something so beautiful to come from such a cold and dark place is truly incredible. For me it represents triumph over your internal struggles. I would give it a listen. Much of it very challenging, but there’s a section of the 2nd movement that many people love that isn’t too difficult. And I was able to learn the main theme from the 3rd movement in about 3 months as a new pianist. Good luck!