She sees herself as “wrecked, solitary.” Her descent into irrationality separates her from other human beings, doing her a member of “some strange race.” Her alienation and inability to communicate are indicated by her being enveloped by silence.
It is a lesson in life, one bigger than I will ever fully grasp.
The end of the poem illustrates that the self will have shattered into pieces or chaos. Their “treading” indicates a pressure that is pushing her down.
The repetition of the word “treading,” gives emphasis and suggests the action.
In other words, her hold on rationality was insecure.
She falls past “worlds,” which may stand for her past.