For my soul is full of troubles - I am full of trouble. The word rendered as “full” means properly to satiate as with food; that is, when as much had been taken as could be. So he says here, that this trouble was as great as he could bear; he could sustain no more. He had reached the utmost point of endurance; he had no power to bear anymore.
And my life draweth nigh unto the grave - Hebrew, to Sheol. Compare the notes at Isaiah 14:9; notes at Job 10:21-22. It may mean here either the grave, or the abode of the dead. He was about to die. Unless he found relief he must go down to the abodes of the dead. The Hebrew word rendered life is in the plural number, as in Genesis 2:7; Genesis 3:14, Genesis 3:17; Genesis 6:17; Genesis 7:15; et al. Why the plural was used as applicable to life cannot now be known with certainty. It may have been to accord with the fact that man has two kinds of life; the animal life - or life in common with the inferior creation; and intellectual, or higher life - the life of the soul. Compare the notes at 1 Thessalonians 5:23. The meaning here is, that he was about to die; or that his life or lives approached that state when the grave closes over us; the extinction of the mere animal life; and the separation of the soul - the immortal part - from the body.