The mind doesn't like a void and wants predictability so what we worry about becomes its own addiction that can be conditioned out of over time. I think of anything else, usually what makes me happy, it can be from cars to games, anime, movies, comics, sports, outdoors (seriously just a nice walk outside, nature can be it's own medicine) or even a nice hot bath, jacuzzi, so many things to think about and enjoy. If you really want to condition yourself, make it an all or nothing precondition going forward though. Tell yourself this will be a 3 month test for instance. No matter what, especially after a stutter, you cannot think about it. You may feel a little weight over your head but think about anything else from the above or more instead. What people are saying below that is getting downvotes may be hard to hear for some people for coping but it's 100% true and can be helpful to come to terms with. One thing I did not take for granted when i was younger is how lucky I was to have this stutter over something worse. I remember watching videos about a young girl who had a severe skin condition where she basically did not have the skin she was supposed to, she had to be wrapped in the middle of the night, it was extremely painful and she could not have a long life like the rest of us. I was in tears and inspired by her strength and happiness for the world around here. Understanding that when a real life threatening condition eventually comes for us all, nothing else will be on our minds, every thought and worry we may have had of what others think and more will be trivial, we will actually miss those times. You don't need to wait for it.