Worries can be like bullies and they like to frighten you. If you get cross with bullies and tell them to go away, you get stronger and they get weaker. Do this with your worries. Tell them “Go away”, “You are talking rubbish”, “I am not listening to you, you’re stupid”.
If the worry keeps coming back to pick on you, do something to take your mind off it, like playing with a friend or reading a book, count to 100 while jumping on the spot.
You could draw your worry as a monster and you as a superhero chasing it away. What other things could you say to the worry to chase it away?