you may be suffering with panic attacks mate, I do a bit.

Mine happen first thing in the morning if I am going somewhere I have known about, no reason for it, just suddenly feel panicked and need to get out of there. Happens when i am in a situation I dont control, waiting for someone,something etc

Then feel hot and weak like i am going to pass out, then if i get to sit down for a moment, it passes and I am fine.

For embarasment Try standing at check in, in a rammed airport at 6am. Get to the front of the que, sorting my bags and suddenly start to feel bad.

check in girls says 'nervous passenger' , I say, 'Me, nah'

Then promptly turn round and burry my face in the floor lol!! Get up and walk away as quickly as possible with legs like jelly.