Ruminating is something everyone does at times, it is basically hashing out a concern in your own head over and over, past the point where it makes sense and especially past the point where you make any progress. This is not helpful and can easily rob you of an hour sleep at night. We’ve all been there at some point, about to fall asleep and you start thinking about a comment you made, something you forgot to do or something you need to do the next day.
There has actually even been a bunch of academic research on this topic and rumination is considered an insomnolent i.e. it prevents one from falling asleep, even in scientific terms.
And here there is actually a pretty good technique called Serial Diverse imagining (SDI). The technique has been developed by Dr. Luc P. Beaudoin and it helps scramble your thoughts to keep your mind off what is distracting you from sleeping.
So you would go:
JACKET. Imagine a jacket on a hanger.
JAZZ. Imagine looking out over a Jazz-club.
JEWEL. Imagine a jewel.
JEEP. Imagine a jeep driving on the street outside your building.
And so on… if you can’t come up words, don’t try too hard just jump to the next letter.
Good luck and hope that you will sleep well!