Whenever we feel anxious or unsettled, perhaps, when we are worried about something then the mind goes into overdrive and we imagine fates worse than death.
The best cure for these things is distraction, whatever that may be for each of us. Stick a film on, grab a book, go for a swim, speak with someone, call a friend, go out to the cinema…
If you leave the mind idle, you will simply sit and add more misery and woe, your chimp brain will go to that filing cabinet of past misery and bad outcomes that we all have in our heads and pull out every single file.
A simple distraction will switch the brain off.