You know, there's meds for that if it's a common thing. That said, in the meantime, I'd go with caffeine. Coke family seems to work best if you have the nausea thing going on too. And uh. This sounds weird and isn't something they mentioned in school but...
Find something to suck on. I'd GUESS it's a pressure thing but someone mentioned it once, suggested it to a few people and it seems to work. I'm not sure if that's pyschosomatic or not.