I have not experienced this with vaping really. I know I had those days as a smoker. Especially after a night of hard drinking, i'd feel the nausea right after lighting up a stinky stogie. I can vape through a hangover, no problem.
Sometimes I open my vape collection and get this nagging feeling that I have vaped out my juice stash to the max. But, then I pull out some juices and try my hand at a homemade cocktail. That puts me right back in the mood to vape on the juices I have. I probably have about 60+ different juices to work with (and counting...).
If you feel nausea or anything negative while vaping. Put the device down and see how long your nic addiction will let you go (if juice contains nic for you). I'm told moderation is the key (to anything really but especially habits). I can't live by this, no matter how hard I try, but it's a nice thought and probably works for some.