It is hard to sleep the night before you expect a big fight or you start a new job or you go on a 3 month vacation or you meet the Prime Minister of Namibia. Your brain won’t stop thinking.
Even during the day, your lizard brain will flood you with things that you should worry about. If you listen to it for more than 30 seconds and believe it, you will always imagine yourself broke and homeless in a week or two. Better things to ponder and allow to fill your imagination:
In conclusion, brothers, focus your thoughts on what is true, noble, righteous, pure, lovable or admirable, on some virtue or on something praiseworthy.
(Philippians 4:8,9 Complete Jewish Bible)