Is it incumbent upon me to stop trying to earn money from publishing online, after I read the Hadith: "Whoever learns a knowledge by which the Face of Allah is sought, yet he does not learn it except to gain a worldly عرضًا, he will not find the fragrance of Paradise on the Day of Resurrection"?

If you mean earning from publishing lectures related to Hadith (definition), the Prophet's biography (Seerah (definition)), and beneficial sciences with the intention of benefiting others, then there is no harm in it for you. Rather, you will be rewarded for it, Allah willing. The Prophetic Hadith concerning those who seek knowledge for worldly gain only does not apply to you, as the warning is specific to those who seek knowledge for worldly gain and not for the sake of Allah. Therefore, you are not required to stop publishing these lectures.