In your discipline, if doubt comes let it come. Do your work - let doubt carry on with its work and see which gives up first!
My life is split in three parts; I don't know the percentage. One could be called "chess" - the Kasparov Chess Foundation, promoting the game, training young players, playing on the internet, sometimes exhibitions. The second area would be "writing" - books, articles, Twitter, Facebook. And then "political activity" - fighting for human rights and democracy, so TV, interviews, speeches.