The Pit

The pit symbolizes Hell. Pits and holes are used as a symbol in a lot of literature, often as a reference to the Pit of Sheol in the Bible, which most Christians read as a reference to Hell (though historically speaking, the Pit of Sheol was a literal burial pit outside of Jerusalem). The speaker imagines himself in this pit before he is able to extricate himself, showing the individual spirit's triumph over Hell and darkness.

Blood

Blood symbolizes suffering. The speaker is covered in it, metaphorically speaking. It serves as an evidence of physical pain, particularly apropos in a poem that represents a speaker's physical disability and suffering in the midst of constant illness.

The Shade

The shade symbolizes death. The poem has a negative outlook on death. The speaker does not seem to believe in Heaven: all that he imagines awaiting him after...