Thanks for the reply, Sherry.
I do take Singulair these days, and remember that it made a noticeable difference once I convinced my docs to let me take it. It's weird how reluctant they were to do that, though, even though finally the symptoms were SOOO obvious:
One day in summer I drove to a town 45 minutes away. When I had the windows open, I felt chest tightness with shortness of breath, and scared that I wouldn't be able to breathe. When I rolled the windows up, the sensations went away in 3-4 minutes. Windows down - breathing troubles back. This went on all afternoon, but I tried to tell myself it was anxiety (that's what all my docs had been saying) and deal with it that way. When I got home, I noticed that being inside the house made me feel fine. Sitting outside on the porch brought the symptoms on again within 2-3 minutes and so I finally decided enough was enough and went to the ER. Even then, the ER doc said she couldn't think of anything to treat me with - that there wasn't any condition that made you short of breath outdoors but not indoors! She gave me Singulair at my insistence, though, and it has helped.
What do you take to help the break-through symptoms?