What country are you from? Get a peptest done - even if you have to fedex the package back to the UK - that will tell you if you have pepsin (from your stomach) in your throat. If you have then you are refluxing gastric contents into your mouth.
I have just done one, and the results are off the charts!! I have been told to forward it to my doctor - this would be the idiot Gastro that says I don't have any reflux at all as my PH study last year was fine. The man has obviously never heard of silent reflux and that things change!
All you do is spit saliva into a tube, I would recommend doing a few tubes, and Harvey emails you the result asap.
Hope that this helps.