I'm having difficulty breathing after accidently inhaling "dust remover" - what can I do?

Use your inhaler. If you have asthma you are probably having an acute asthma attack. This is a result of spasm of the breathing tube muscles. Bronchodilators like albuterol (proair, proventil, ventolin), Levalbuterol (xopenex (levalbuterol) & Pirbuterol (maxair) rapidly relieve spasm restoring normal breathing. Next time wear a face mask and open some windows for ventilation.