Rain, Sleat and Snow

Well, some of my first winter runs have been a little tougher on me. Seems like my asthma is not getting any better. Guess it is time to visit the Doctor. The cold air tightens up my chest and makes it very hard to breath. I try to run tough the pain and light headiness, but but the time I am just about done I hit "the wall" unable to push though any longer and ready to crap out. How am I ever going to get through the winter?