The repetition of "come" and "to bed" emphasizes her frantic, cyclical thoughts, which are a stark contrast to her earlier command of language.
This dramatic moment is often used in acting classes and literature studies to show "character development through breakdown". come_give_me_your_hand
For your reference, here is the immediate draft of that section from Shakespeare's Macbeth : The repetition of "come" and "to bed" emphasizes
It is spoken by in Act 5, Scene 1 (the famous "sleepwalking scene") as she relives the guilt of the murders she helped commit. Context of the Text come_give_me_your_hand