Dang, this did give me a panic attack. The sort of thing OP describes is my greatest fear, and I have a hard time dealing with the fact that it really happens to some people.
To be fair, I suffered anxiety since I was 7 or 8yrs old and had a shitty start at life. That snapping experience was a long time coming for me. Don’t be worrying it will happen to you, cause it’s pointless unless it has happened and it’s not worth the worry.