The psalmist is feeling intense spiritual thirst, a barrenness of soul, and a strong need for God.
He combats that by reminding himself that he can trust and put his hope in God, by remembering God (bringing Him to mind), and by singing praises and praying.
I do have down times, though none as intense as described by the psalmist. My inclination is to hide my feelings from everyone, even those close to me, including God. I am learning to make myself lay everything at His feet, search His Word for encouragement and guidance, and pray even if I don't feel I'm being heard. Once I can do those things, He pulls me through, often with remarkable speed. God is faithful!