This song is about addiction. Try look at it through the addict's point of view.
This a great song! His a slave to the drug and he loves it. Even the melody reminds us of the slave working songs, right.
No matter what he does he will always go back to "her". He will crawl back to.
He tried going cold turkey. The first 3 days are normally the hardest to do. The reference to the fever, the will to die, all that section is about the pain he was going through.