He lay there for many days may be rendered “Antiochus lay in bed day after day.”

Because deep grief continually gripped him: For grief see the previous verse. This clause may be rendered “because he became more and more depressed.”

And he concluded that he was dying may be expressed as “until he realized [or, came to the conclusion] that he was dying [or, going to die].”

Quoted with permission from Bullard, Roger A. and Hatton, Howard A. A Handbook on 1-2 Maccabees. (UBS Helps for Translators). New York: UBS, 2011. For this and other handbooks for translators see here.