I also take a pill of Loratadine, which should stop the allergy symptoms. But it looks like it's not working, so my coughing might not be cause by dust allergy.
@causa_arcana I visited a doctor on Monday, and the doctor gave me Singulair and nebulizer treatment for preventing asthma. I don't know if that's working, since the improvement is not stable, sometimes it feels better, sometimes not. But judging from last night, I was waking up significantly less, so maybe I'm on the right track.