MCA has just told me this, and I thought of posting it here for all:
Only worry about things you can change. If you can, do something to make it better, then stop thinking about it. Things you can’t change aren’t worth worrying about.
For each situation, ask yourself “what’s the worst that can happen?” The worst is usually not that bad
If I could follow this, maybe I will stop worrying about everything and anything, even after a decision has been made and the event is long gone.