Loss of Taste

I am a 57 year old female that has been experiencing a loss of taste for almost 2 weeks. I had dental work done 2 months ago, take nexium for acid reflux, and synthroid for thyroid and klonopin for anxiety. These medications I have been taking for years and doubt that I am now getting a side effect of this taste of everything tasting "bland"!! I have been seen by my primary care Dr . with blood tests including thyroid and ANA and all are fine. My doctor seems to think I have a sinus infection but I don't have any symptoms except now I am getting alot of post nasal drip and tenderness on my cheek bone near my nose. I am going out of my mind not being able to taste anything. Does any one have any suggestions as to what I have or is anyone experiencing any of my symptoms now or in the past. Please help!! Thanks, Maria