Man, I take back everything I said about using punctuation--this poem wouldn't have, like many others said, that sudden, fast-paced intensity with punctuation. I also like the repetition of the line "clock is tickin." We're all living to die, in a sense, and time is the reality of that notion.
It must be a very tough situation to be in, one which I dare not imagine. Your short but, very effective write gives the reader the sad picture of what it could be like. I pray that more effort and time is put into finding more effective cures rather than inventing newer and uglier killing means.