See, asthma is an allergic condition where your airways are narrowed due to your Allergic tendency. How much they are narrowed, can be measured by a Pulmonary function test. Till the airways are not too much narrowed, you may not get breathing difficulty.
So in asthma, inhalers should be used regularly and not SOS only. As on a longer time without taking inhalers, if your airways are narrowed, they will start becoming narrower on a permanent basis and your lungs may become weak.
Next Steps
consult a Pulmonologist, do a Pulmonary function test and start taking inhlaers as advised by a doctor regularly