happens to everyone, i don't know the exact cause of it, but it used to happen to me when ever i started falling asleep. It seems normal, only because it wont last for a long time. When it triggers, keep to a steady breathing pace, drink lots of water, and if you have asthma, use your inhaler when needed. thats about all i can tell you. Try not to think about it either.
That' s exactly what it feels like
I think i feel you there, dose it sort of sometimes feel like your heart skips a beat, and seems like your a little out of breath at that second?