I too am a Gemini introvert (Sun cj. Saturn) and most would believe that to be an oxymoron! lol! I do suffer from incessant mind chatter and to try to circumvent this by visualizing or simply being aware of the energy flowing upon the point I am working on. Sometimes that escapes my attention so then I try to focus on breath. In my experience the energy still flows regardless of where my thoughts are but it does flow better when I'm able to concentrate on the energies.
Hope you find success and when you do, it would be kind for you to share your technique.
I appreciate reading your message.
-aum