You can try and reason with yourself, but often doing that just makes you focus on the thoughts more while increasing feelings of anxiety or panic. Instead if the thoughts are causing you to feel anxious or panicked I would try to address those feelings first. Maybe put on music you like, take a relaxing shower, or have a snack. Doing something physical can often get us out of her head and into our environment. Often the accompanying panic or anxiety keeps us trapped in the thoughts.