These words from Sirach 2:3a,4-6a motivate me and re-direct my thoughts (from myself to others) when I am finding things difficult:
Cling to Him, do not leave Him,
Accept whatever happens to you;
in periods of humiliation be patient.
For in fire gold is tested,
and the chosen, in the crucible of humiliation.
Trust in God, and he will help you…
This prayer helps me to grow in humility.