Hello and a happy morning!
“The more you think of unhappy thoughts the more you get upset.” It is true. Guys, break the chain then.
When one unwanted thought takes a place in your mind for little longer time, beware. This will unknowingly trigger another unhappy thought.
To stop this just remind yourself that you have read this piece. Seriously, remember that you are aware that when such things happen you need to break the chain to free yourself.
As per the requirement act accordingly. It could be just leave the place for the moment, it could be engage yourself in other work of interest, it could be to eat an ice-cream or it could be to open up an old memory of your photo collections. Anything!
Determine what suits the situation, distract and fee yourself. Later you will find the best solution and things will seem easier.
Try when caught.
Good luck.