A short song of impatience. How long! He almost seems to jeer God, saying he must have turned his back, or forgotten him. After all at the end he recognises that God is faithful. When the prophet Elijah made fun of Baal he asked his followers if Baal was on the toilet. This is not as rude as that, but it’s coming from a similar place: where are you god?
With Baal the context was doubting his existence. Here there is no doubt, here it is ultimately impatient belief, he knows God will be faithful and is real, but it’s hard, it’s hard.
Living in the world as a believers will sometimes be hard. The bible makes no bones about it. The psalmist makes it clear that you don’t have to be silently stoic about it either. Tell God, plead with him.