This reminds me of writing „morning pages“. I first heard about it when stumbling upon „The Artists Way“ by Julia Cameron. To get rid of your mental baggage, you should write three pages every morning, she claims. The book is mainly about finding your (lost) inner creativity. But i have generally found that this routine helps to clear blockages in the mind and to become clearer.
Just write your jumbled thoughts, what you write doesn't necessarily have to be coherent imo.