Hi Carol
I've had this before, where I'm having a good time and them bam it happens. It's probably where you were walking about then sat down.
You've probably had this before and your still here!
I'm having a rough time too at the moment feeling anxious weird beats or feelings, but I have to remember that for me it's the time of the month and this in turn heightens my anxiety, which irritates my stomach which in turn gives me wind, and then the wind and irritated stomach irritates my Vagus Nerve. Try to think logically I know it's hard, especially with not knowing the results of your tests, which I'm sure will show that everythings normal.
This time of year as much as it's enjoyable is also quite stressful, Your fine try to put that episode behind you as hard as it is but the more you worry about it the more you're keeping yourself anxious, try to think positively and look forward to this time next week.
Enjoy yourself this christmas and new year x
Kath