Patricia - you've been through an ordeal... wow. But I'll agree with the other posters about salivary recovery. My mouth was like the Mojave for months and months, maybe a year. But gradually around 12-14 months it started to return to some kind of normalcy. Nothing like before, but much better. In fact now, maybe 26 months after my last trip on the ride (as I called RT), it's even better than it was 6 months ago.
I never tried any direct medication for this but if it's out there, why not give it a shot?
Keep us posted. Thinking of you.