I had this a couple of years ago, I remember how awful it was so I feel for you Rockchick. I used to suck ice-cubes when it was really bad but it only helped while it was in my mouth. My GP gave me a saliva substitute as she thought it might dry mouth in my case. I think it lasted about 3wks then gradually went away but I do get it occasionally it might last a couple of hours or a few days but its never so bad as that first occasion.
It appears there is no cure and there seem to be various causes . They do say chewing gum can help but I didn't find it was any good .