A lot of people think those words but never utter them. You could wear an elastic band on your wrist and snap the band each time you think the words. This will ( excuse the pun) snap you out of it.
I don't swear. I have strong aversion against it, yet I'm now in high school and i constantly hear the words in my mind. I never say them, but it concerns me that I'm saying it in my head. How can I stop it? (Serious answers, please).
Being in high school you are probably hearing those words more now than ever. Many high school kids think it is cool to speak that way and is a safe rebellion. With it being said around you more, it is likely to come into your thought process. As long as you are aware it is there and make the effort not to say them you will be fine. It will actually save you breaking the habit when you are looking for a job later.
Just replace it with a catchy tune in your head . . .
It has been said that everything you do 12,
times or more becomes a habit.
You started this, you can stop the same way.