Asthma with Normal PFT's and CXR

I was diagnosed with asthma in 1996 during my last pregnancy at 37. I have had several hospitalizations due to frequent exacerbations. I am an RN of 22 years. I am no longer working due to increasing SOB on exertion, and these exacerbations.
I went to a pulmonologist , and subsequently had PFT's and CXR which were grossly normal. I am confused, as I use my nebulizer 4 times a day and my rescue inhaler prn during the day for shortness of breath. Even though my PFT's were normal, she continued to keep me on my Singulair, Pro-Air HFA, Xopenex and Albuertol for my neb., Spiriva, and the new inhaler Symbacort. My question is this: If my PFT's are normal, should i be taken off my meds?
Note: I was told to go without inhalers and all meds 24 hours prior to PFT's, I ended up in the ER , and was discharged 2 hours prior to PFT's, which my pulmonologist said , that didnt cause my PFT's to be normal. I am confused, why after 11 years, and many ER visits, and 4 hospitalizations, would my PFT's be normal, and what does that mean in regards to my ?? Asthma. I am a smoker, trying to quit.

[National Jewish Health]

The obstruction to airflow, characteristic of asthma, can vary greatly, often within a very short period of time.  You should not go off your meds, just because the PFT's are normal at any given time.  Normal spirometry does not exclude the diagnosis of asthma.  The diagnosis is made objectively by either: 1) the demonstration of a bronchodilator effect of >12-14% or, 2) a methacholine challenge.  If both of these is negative, the likelihood of your having asthma is low.  

Another condition, Vocal Cord Dysfunction, can mimic asthma or actually occur with it.  This is caused by inappropriate closure of the vocal cords, especially during inspiration.  This diagnosis can be made by direct observation of the vocal cords with a fiberoptic laryngoscope, during an attack or by evaluation of the inspiratory flow loop, on pulmonary function testing that includes both inspiratory and expiratory loops.

You should discuss the above with your pulmonologist.  Good luck with your attempts at smoking cessation.