I was prescribed Singulair in an attempt to prevent nasal polyp r...

I was prescribed Singulair in an attempt to prevent nasal polyp regrowth following a third sinus surgery. Began taking it on February 2, 2007. After about the first week noticed difficulty sleeping. Would wake frequently and then have difficulty going back to sleep. A couple of nights later, I had a sensation that someone was standing over me and choking me. I awoke screaming at the top of my lungs. Next, came the depression, total feeling of impending doom, death and misery. I cannot put into words. Would go get a haircut and wonder if this was going to be my last and would it look good in the casket. Next came the lethergy, I would wake up exhausted, sit on the couch all day, watch tv then go take a nap and go to bed at 6 p.m. Other side effects I noticed were total loss of sexual desire or ability to attain or maintain an erection, headache, and digestion problems. I stopped taking this on March 7 and am slowly (very slowly) returning to my former self. Does anyone know how long it takes to get this out of your system totally? - I have never had any issues with depression or sleep in the past so am convinced these issues are related to this drug.