What's nice about writing. One can interpet the lines as they see it. I took the word "Mad" as insane. He wasn't merely angry with the situtation, he was insane as the murder in the "Tell Tale Heart".

Behold:

TRUE! --nervous --very, very dreadfully nervous I had been and am; but why will you say that I am mad? The disease had sharpened my senses --not destroyed --not dulled them. Above all was the sense of hearing acute. I heard all things in the heaven and in the earth. I heard many things in hell. How, then, am I mad? Hearken! and observe how healthily --how calmly I can tell you the whole story.

Words have meanings. This is mad!