the reason your not feeling better is you also have to control your diet when you have LPR..
google the koufman diet. high PH Diet anything acidic like a diet coke will make it worse.
thats also a simple test if try to drink something acidic like a diet coke does it get worse, if so its probably LPR...
diet is a trial and error thing with lpr.
try the following
personally high PH and paleo work for me.
its takes a while to figure out the right diet... months to years..
you know your on the right track when your throat gets better month to month..
the 2 test you should do:
dual probe ph test (like the restech)