i cured an asthmatic condition by completely eliminating dairy for about 9 months. after that i was able to once again eat dairy in limited amounts. you may want to try that.
there is someone in the oxygen forum who has been using a C-pap machine with hydrogen peroxide added to the water at night, and says that the results have been amazing. someone else used hydrogen peroxide in an inhaler to cure his asthma. you might also want to check into something like that.
asthma can be triggered by allergies. you may want to investigate an elimination diet, which is a way of systematically testing what your body may be allergic to and then eliminating that from your diet.
an good applied kinesiologist can be very helpful in cases like this. i would look into that, its a way of gaining a lot of knowledge about your situatuion relatively quickly.