Psalms 31:9-10

Have mercy on me, O YHWH,

For I am in distress,

My eye wastes away with grief,

Yes, my soul and my body.

For my life is spent with sorrow,

And my years with sighing,

My strength fails because of my iniquity,

And my bones are wasted away.

But suddenly his expression of confidence cease to be replaced by a plaintive cry as he considers the years that have gone by which have been filled with sorrow and sighing, and with an awareness of sinfulness. He is filled with deep distress. Indeed he feels that he is wasting away with sorrow. And this is essentially seen as connected with his own sinfulness. This suggests that in the previous verses he has been praying ‘through gritted teeth', and that he is triumphant in spite of having a difficult life, not because he is having an easy one, and now he faces up to the present reality.