Rhetorical questions expressed David"s frustration and sought to move God to action (cf. Psalm 6:3). God had apparently forgotten His servant or was hiding from him (cf. Exodus 2:24-25). Having no word from the Lord, David had to listen to his own reasoning that he regarded as a poor substitute. In the meantime, his enemy continued to enjoy the upper hand. [source][source][source]
" Psalm 13is indeed a speech of disorientation. Something is terribly wrong in the life of the speaker, and in the life of the speaker with God." [1][source]