I remember once talking to an elderly man who had manned an anti-aircraft gun in England during World War Two. His gun emplacement was positioned above the cliffs of Dover on the south coast, and was the first line of defense against the waves of German bombers that swept in across the Channel. That also made it the first target for the fighters that accompanied the bombing raids. I commented that manning that gun was an incredibly brave thing to have done, and I'll never forget his response. In other words, he was too busy trying to shoot down bombers to be worried about his safety.
Action is an antidote to worry because it's cathartic.
The trick is to take the right course of action for the problem that's worrying you. One of the purposes of this book is to help you perfect that trick.