My nasal allergy symptoms were no longer controlled by daily Alle...

My nasal allergy symptoms were no longer controlled by daily Allegra D. The doc prescribed Singulair and told me to take it at night. I asked about side effects and she said, "none". After the first dose I had mild diarrhea the next morning. After the second dose I developed a bit of a cough and had more diarrhea. I took the third dose last night and shortly after began wheezing and coughing (I do NOT have asthma). I could hardly breathe all night because of the phlegmy cough. Also felt nauseous. I don't feel sick like with a cold or anything, just can't breathe. I'm so glad I found this site! I will not be taking any more Singulair. I hope I have not caused lasting damage to my lungs. Wondering if anyone of you who had a similar reaction could tell me how long before this self-caused cough clears up?