That is pretty much what I experienced, so I wouldn't get too worried about it. From start to finish, my wall paper paste lasted 21 days exactly. At times near the end, it abated for a while, then would come back. It eventually ended for me and will for you too. In my case it was just like someone flipped a switch and it was no more.

As for what you can do, I found that using those external nose strips (Breathe Right) enabled me to keep my mouth shut while sleeping, thus avoiding the horrible dry throat. And five years ago Brian posted a tip I found worked for me too -- press your tongue against the roof of your mouth, then swallow (while mouth is closed) and that helps to keep it closed.

Welcome to this forum. Just about any question you can post will get a response from someone with personal experience to relate.