Baseball simile
Snyder uses a simile to describe the abscess in his liver, comparing it to a baseball. This gives us a sense of the seriousness of his illness.
The public malady
In order to express the idea that there is an inherent "illness" within American society, Snyder uses the metaphor of a "public malady," suggesting that society as a whole is afflicted.
Rage
Snyder uses a metaphor to describe how a feeling of rage kept him going through his illness. He describes it as being "a torch that ignited amidst kinds of darkness I hadn't known before."
The chamber of sheets and tubes
Writing about his stay in the hospital, Snyder uses a metaphor to describe his "chamber of twisted sheets and tubes." By using this metaphor, he depicts how uncomfortable his stay was.
Lonely light
In describing his isolation, Snyder uses a metaphor: "I didn't want the torch in my mind to be a lonely light." Here, he is speaking about his sense of rage, and the fact that he wanted to find others who felt the same way he did.