I'm 45 (male) and never had asthma until a year ago-- it came on ...

I'm 45 (male) and never had asthma until a year ago-- it came on after a severe bout with bronchitis. The doc gave me Prednisone for a week, I also took Advair, Flonase, Aciphex (a stomach pill), and Singulair. After a few months, the asthma seemed to be gone, but the doc had me stay on Singulair (one per day, at night before bedtime) to be sure it didn't return. Before the asthma and Singulair, I had stomach problems (diagnosed as gastritis) and some stiffness in my lower back. But for the past year, my stomach has been AWFUL-- even the meds don't help. And the stiffness has been really bad: I would have to stretch my hips, legs and feet, and stay in the hot shower as long as possible. I even had frequent bouts of diarrhea, which I attributed to the Aciphex-- but now I'm thinking it might have been the Singulair. I discovered this site a few days ago and stopped the Singulair. I THINK my stomach is getting a little better, and some flexibility has returned. Of course, my nose has started running and my breathing isn't the greatest--but I'd be willing to deal with it if my stomach and muscles feel better. IS IT POSSIBLE MY STOMACH PROBLEMS AND STIFF MUSCLES/JOINTS HAVE BEEN EXACERBATED BY SINGULAIR? If you've had this problem, please post a reply. How long will it take for the side effects to disappear?