Some individuals have a sensitive predisposition or personality, as a result of which some triggers ( which might be insignificant to others ) might lead them into a chain of thoughts that are predominantly negative.
It should resolve by itself, however if it’s persists and leads to distress - low, anxious mood, sleep disturbances and difficultly concentrating on the tasks, then it is advisable to connect to a psychiatrist to make sure there isn’t some major problem that might need counselling or medications
Next Steps
Try keeping yourself busy - Reading, exercises, yoga ( pranayama, Surya namaskar ), meditation, connecting with your support system - friends and family.