Sometimes a change in diet can be helpful. Asthma is a kind of inflammatory reaction, so things that trigger inflammation in your body can trigger asthma. Some possibilities of things you can do to help your asthma include:
Reduce stress
Get good sleep
Try a food elimination diet such as the Auto-Immune Protocol to see if you have a food trigger
Use an air purifier especially in the bedroom if air quality is poor where you live
Hope one of the suggestions in this thread helps.