Respond immediately, rather than analyzing or stalling.
"He who hesitates is lost." -- Cato
Anticipation of an event is always more extreme than the event itself -- for both positive and negative events.
Just do it.
Train yourself to respond immediately when you feel you should do something. Stop questioning yourself. Don't analyze it.
Don't question if it came from God or from yourself.
You'll figure out what to do after you've taken action. -Until you take action, it will all be hypothetical. But once you act, it becomes practical.