Yorkshireguy, good luck with the doc. and I hope you get some solution to this.
It's been a recurrent problem for me but I often feel it more in my nasal passages, as though there is a marble up there pressing down on my throat. I had it severely last summer which coincided with domestic upheaval, I'd start gaging as soon as i woke up. It gradually subsided as things calmed down for me and I now think there could be an emotional element to it.
some time ago i read on an american website about a condition called something like "oesophegal webs" which I thought I might have as whenever I try and swallow a tiny tablet it feels as though it's trapped in my throat for hours. It drives me nuts!
Hope you get sorted soon. sagey.