Listening to positive affirmations

Q: I have a question about something called positive affirmations. 

I pray the five daily prayers and the Sunnah, read the Qur’an, fast, and do a lot of supplication to Allah Ta'ala. But I like to listen to positive affirmations to improve my mood, for example to achieve a certain thing that definitely comes from Allah Ta'ala, so my intention is not shirk. The affirmations do not contain any negatives or against Islam. 

Is this considered polytheism if I still have complete trust in Allah Ta'ala? Is the law of attraction permissible? What is forbidden in subliminal messages? Or in subliminals in general?