Rejoicing is an act of choice. It comes from the heart and mind that is fixed on God. There is so much temporary (non-eternal) stuff that competes, making the choice hard because our heart and mind get clouded. Find your purpose and strength in Him alone who can satisfy and choose honor Him.
Isaiah 61:10
I will greatly rejoice in the Lord;
my soul shall exult in my God,
for he has clothed me with the garments of salvation;
he has covered me with the robe of righteousness
Habakkuk 3:18
I will take joy in the God of my salvation.
God, the Lord, is my strength
Psalms 13:4
But I have trusted in your steadfast love;
my heart shall rejoice in your salvation.
I will sing to the Lord,
because he has dealt bountifully with me
Psalms 35:8
Then my soul will rejoice in the Lord,
exulting in his salvation
Luke 1:46
“My soul magnifies the Lord,
and my spirit rejoices in God my Savior