lists that will save your life...
This three columned list* has helped me deal with fear and anxiety,
Column 1: What do you fear happening, be specific define your fear.
Column 2: What can you do to prevent that from happening?
Column 3: If it still happens, what can you do to remedy it?
Just making the lists, and planning out scenarios, gets those roaming thoughts out of your head and onto paper, you don't need to worry about that thing anymore, you've made the necessary plans.
After all, "We do suffer more in our imagination than in reality" - Seneca.
Get skin in the game, get it down on paper.
Pierre
*I first heard a version of this technique from Tim Ferriss in his TED talk.