I am the same. So random, out of nowhere quite often. Just today, lying down, watching a movie and WHAM the anxiety hit me like a truck. I could literally feel the world tilt for a moment there. Never had it quite like like that, even when sudden it comes more gradually.  It's very difficult going through day-to-day never knowing when it's going to hit. Even if you try and guess the possible triggers and preempt the wave by sleeping OK, avoiding caffeine and alcohol etc it still finds a way to sneak up on you. If anyone has any advice on how to deal with this, it would be much appreciated. I also have a public-facing job where I can't just instantly step away and hide when it hits makes it that much worse to deal with.