A state of extreme suffering and deep despair can overwhelm a person until hardship seems to consume their entire existence. The soul becomes completely filled with troubles, reaching a breaking point where it simply cannot contain any more pain [רד״ק, מצודת דוד, שטיינזלץ]. Commentators offer different views on the exact nature of this suffering. It may refer to severe physical illnesses that rack the body [אבן עזרא]. It also highlights a bitter contrast to the way a natural, peaceful life should end. Instead of growing old and feeling satisfied with a long life of goodness and peace, the individual has endured days paved entirely with hardship, becoming full only of sorrow [מלבי״ם].
As a direct result of this relentless suffering, life is pushed to the very edge of the grave. The primary approach among commentators is that the idea of life reaching the depths of the earth is a metaphor [אבן עזרא]. It expresses how a person's days have drawn so incredibly close to the grave that they are practically touching death.
Beyond the personal experience of pain, this deep despair can also be understood on a national level, with the speaker representing the collective Congregation of Israel [רש״י]. From this perspective, the overwhelming troubles are the harsh and bitter agonies of exile, which have brought the entire nation dangerously close to death [רד״ק]. Alternatively, this collective suffering points back to the Israelites who wandered in the wilderness. Their grave sins, such as the Golden Calf, brought about severe punishments and disasters, dragging the survival of their generation to the very brink of the grave [אלשיך].