The human mind is extremely good at simulation. You can think of something, imagine it being real, and then experience it as if it were real, feeling all the emotions and having all the physical responses as if it were real. While this is great when you’re in control of your imagination and using it for a purpose, it is frightening when your imagination runs wild and controls you. Often times an irrational fear is when an encounter with something you fear triggers your imagination to take over, and all you can think about or feel is all the things that could go wrong or that you can imagine happening that you don’t want to happen. What you need to do is take control of your imagination to avoid the problems that arise when you are not in control.
Instead of letting your imagination run wild with no explicitly stated goal, focus it. Why are you imagining things, what do you want to accomplish? If you find yourself constantly scared by the horrible things you imagine could happen, be self aware and realize that you have subconsciously decided to imagine all the things that could go wrong. Instead, re-define the goal to be to imagine possible outcomes without bias, and make a clear level headed decision (Decision Making Rich vs. Poor). Better yet, imagine all the ways it can go right!
Furthermore, apply the lessons from the article Lost and Found to your fears. Simulation and Imagination have great power, and “with great power comes great responsibility.”