It's gone now.

Upper pharyngeal web,  apparently.  When the surgeon waved his hands about and showed me how he'd got rid of this "extra skin inside"  I had no doubt as to why I was sore.
Ongoing investigations as to why I'm having throat, speaking and stomach problems.

**Back blipped  and it turns out that upper pharyngeal things were nothing to do with it!  but it's gone now!