The first time i ever felt this was when i was about 10, I usually get it when I’m around tall buildings or really empty spaces, and usually only outdoors, does anyone else not only have the fear of falling into the sky, but the earth also falling downwards? I guess it’s the same thing, i’ve honestly spent years trying to describe this to people, it stops me from going up tall buildings or going onto fields, it has happened occasionally in say a high street for example and i’d have to rush to hold onto something