There are a ton of folks with asthma who ride, including me, but many of us are lucky to have mild cases. I haven't had an asthma attack in years, but I do wheeze/cough at night if exposed to allergens. I use albuterol before rides on which I expect a lot of pollen or other air issues, but generally don't need it. I used to use Advair daily as a preventative, but really didn't think it helped much, and it is $$$. Once I found out that it could predispose to osteoporosis, I stopped taking it.
Good luck in sorting out your issues. There should definitely be a way for you to manage your asthma so that you'll be able to ride and not have asthma attacks.
Emily
2011 Jamis Dakar XC "Toto" - Selle Italia Ldy Gel Flow
2007 Trek Pilot 5.0 WSD "Gloria" - Selle Italia Diva Gel Flow
2004 Bike Friday Petite Pocket Crusoe - Selle Italia Diva Gel Flow