Welcome to HealthcareMagic forum.
It seems like you have some kind of obsessive illness.
is a mental condition where a person has repeated recurring thoughts. The thoughts may be limited to a particular episode (like in your case) or with many other similar thoughts. This condition can be treated with the help of medications and behavioural therapy.
At the age of 13, I do not think you will be allowed to directly consult a doctor. Hence I recommend you talk to your parents or a guardian about your thoughts. Consulting a psychiatrist
for therapy and medication will resolve your symptoms.
Hope this helps.