Psalm 77:3:

I remembered God, and was troubled: I complained, and my spirit was overwhelmed. Selah.

See also:

Objection: David Was Honest Enough to Sing to God About His Sicknesses; We Should Pray “Honest” Prayers Like His Rather Than Saying We’re Healed When Our Bodies Say Otherwise
Condition: Weakness
Should I Use Positive Thinking to Be Healthier?