Psychocybernetics, while some of the data is completely off the rails and itself is a dated book, actually helped me get better sleep. Unlike Miracle Morning, the book heavily emphasized visualization as a way of actualization of goals and thoughts. Having a negative script and using viewing a mind as a machine that produces a negative product will, in essence, cause you to have a negative outlook on life.
However, viewing your mind as a machine with a positive narrative causes you to unlock your potential. It is true that the way you act is a total result of how you view yourself.
Consider the statement "girls are bad at math." This can be a self-fulfilling prophecy in our classrooms because women are taught that they may not be good at being an engineer. Because their narrative reinforces that they are incapable of understanding mathematics, it becomes true for some. Consider reading this article on stereotype threat that explains this phenomenon further.
Once I started looking at the negative elements of my narrative, I wasn't so scared anymore. Honestly, because I started viewing myself in an even more positive light, I was more relaxed in the evenings.
Overall, it's a great read. While I read it in the morning, I would highly recommend this as a bedtime read as well.