The psalmist chooses the latter. The past is for instruction, not mere nostalgia. Obviously Psalms 42 and 43 were each ending with the same refrain. In the words of this refrain the psalmist speaks bluntly to himself. Notice the question he asks himself.
Faith also asks why, but goes on to act.
If we do this, the change in the way we feel may not be 'instant', but if we go on trusting God even when it's hard, things will improve. PRAY Pray for anyone you know who is in trouble.