I just read the Feynman text you linked, and it was inspiring. When I started programming, I did it because I enjoyed it. I found it fun. I was just exploring it. Then it became my career... and over the years, it's become more about being good, making money, and being "proud" of my accomplishments.
Maybe I need to take a step back, address my anxiety, and get back to playing. Easier said than done, but worth doing.