I am 39 years old. I was prescribed Singulair last month. I have...

I am 39 years old. I was prescribed Singulair last month. I have bad allergies and have started to develop some asthma type symptoms. My doctor decided to try me on Singular before giving me an inhaler. I took the Singulair for 2 week and had to quit. After the first day, I developed a headache that would not go away, nausea and very vivid bad dreams. This lasted the entire two weeks that I took Singulair. I thought that after maybe a week, some of the side effects would go away but they didn't. So, I quite taking the stuff. I will never take it again. I am back to my Zyrtec for now.