The ballad that is contained within Edgar Allan Poe's story The Fall of the House of Usher is indeed depicting of the state of affairs of the proprietor of the mansion, Roderick Usher.
First, the name of the ballad is "The Haunted Mansion" which is pretty much the situation of the establishment of the Ushers: A place which once may have been sumptuous and quite comfortable, luxurious and perhaps even regal. And, yet, with the advent of time and the untimely cursing that seems to have come over the Usher clan, has deteriorated into a shadow of itself: Moulded, abandoned, and decayed.
In the ballad, perhaps the one stanza that relates more directly to Roderick Usher is when it says:
But evil things, in robes of sorrow
assailed the monarch's high estate
(ah, let us mourn, for never morrow
shall down upon him, desolate!)
This is a direct description of Usher's situation as a man who has befallen under a curse that has ran down his entire existence.