What used to help me the most, whenever I was terrified, was to not argue with myself over my fears but rather directly assess my current situation. So, if I were frightened, I would check for obvious danger:
- Earthquake happening?
- Flood?
- Fire?
- Person with a rifle or other weapon?
- Known perpetrators in the room?
- Are the people around me calm, look like they're feeling safe, or are they frightened, too?
I'd work down my brief checklist. If my answers came up negative, I'd then admit that my current environment was safe, which meant my fears belonged somewhere in the past - certainly not in the present.
This was enough to allow me to realize I was actually safe NO MATTER HOW I WAS FEELING. Such a reality check helped me to slowly back out of my terror.
The more I practised my checklist approach, the easier it got, and I ended up experiencing fewer episodes.
So, I suggest that, whenever frightened, you literally look around the room for danger. If you don't see danger, you can assume you are safe and that the fear belongs in the past.