tickle cough

I have tickle cough since August.My doctor thinks I have post nasal drip and gastroesophageal reflux.He prescribed
some inhaler and proton pump inhibitor.It did not help after 2 weeks.Chest xray was done and it was normal.My
PULMUNARY FUNCTION TEST was also normal.My cough comes and goes and sometimes I feel it is some sort of allergy.I tried claritin and sudafed but it did not work either.I was referred to a pulmonologist and I'm now taking
Symbicort 2x a day and Nexium.I started last Oct.27,2009 and it helped for few days.Now the tickling of my throat is getting worst again and I feel so miserable everyday at work and at home.I take cough drops to soothe my throat and it's helps a little.Please help me.What else do I have to do?Thank you so much