Re: Day 16 and experiencing some very ILL symptoms ... halp!
You should not be moving around, and you need to plan your schedule so that you have energy for your job interviews. (I eat an apple on the days I need energy, i don't know if that's appropiate, but its how I overcome it)
You're in healing, and you need to stay in bed like you would with a bad fever. Your body probably just let go of a lot of toxins.
I'm not sure about the water thing, but I hear that you're not supposed to over-do water. You might actually make yourself sick by drowing yourself internally.. You might have a dry mouth because your digestive system is taking a break and saliva is the first chemical process of digestion, so it's stopped. I'm not sure how you can fix it, but brush with a soft smooth toothbrush with warm salt water all over your mouth for 5-10mins to dislodge all bacteria.
Anyway, these are just my recommendations, I'm new to fasting, so if your symptoms get severe then get checked by a doctor who endorses fasting (nearly impossible to find) .. I wouldn't go to a normal doctor, they might lock you away as an anorexic!