James, it sure sounds as though you got a bad deal from some of those docs. Jeesh, you'd think they'd understand what you were going through emotionally at least and treat you better.
But as Christine says, that's all in the past. The main thing is that the RT worked, which I'm going to hope it did. All of those symptoms you described are pretty much textbook and I had them all. It's going to take quite a good bit of time for the excess mucous to go away. The dry mouth will take longer, even up to a couple of years to establish itself at your new normal.
I'm nearly at the 2 year point and I still basically take a swallow of water with everything that's not very wet. I gained 4 extra notes at the bottom of my vocal range, this was after not being able to speak at all for a couple of months followed by a gradually returning voice.
The hair on the back of my neck eventually grew in... mostly. Think it might be a bit less than I had, but I just keep it longer back there. Beard hair returned everywhere but below my jaw on the side of my neck dissection.
Hang in there. Things will continually get better, albeit slower than you'd probably like!
David2