The “near fatal reaction” may have had a component of airway inflammation, that served to “tip-off” your asthma, much as can happen with a severe respiratory infection, such as
bronchitis, resulting in what is called bronchial hyperreactivity, a feature of asthma. What you have experienced may or may not be asthma in the conventional sense but be more akin to a condition called reactive airways dysfunction syndrome (RADS). This latter may take weeks, months or longer to eventually subside.