You have more patience then I do. Salu!
What should explaining the Catholic teachings require patience? It only requires time, but I am finding some.
Exasperation comes from the expectation that your conversation partner will say “Ah, now I understand and convert to Catholicism”. That will never happen on the thread. Much later, — perhaps; but you are not likely to hear from him if it happens. Write for the anonymous reader, not for the heckler that made it his hobby to contradict the Church.