It is definately not an allergic reaction
. It is a mixture of extreme dehydration
(from what it sounds your not drinking any fluids) and Bruxism( http://en.wikipedia.org/wiki/Bruxism ).My advice, no im not gonna say quit, drink a gatorade before doing them or even if you can while doing them. and then nothing but water after that. Unless your up for up to or more than 24 hours, in that case try and drink one every 12 hours. Or you get smart water which has electrolytes already. And also try and ask your dentist
for a night guard for when you do sleep because you have probably (if you didnt have it before)have Bruxism now anyway. :) hope that helps.