I can't eat dry food without water while food is in my mouth. always been like this. ent said everything looked normal. feels like saliva disappears?

Unusual in young: This is very unusual in your age group. First you should look over any medicaitons that you take, including over-the-counter medications that can cause this. Be ware of energy drinks because certain stimulants can cause this. If this doesn't turn up a cause you should see a good primary care physician and you should be checked for auto-immune disorders. Rarely caused by mumps.