The more you engage in obsessive thinking, the stronger it grows. Try to be active and create a nice flow to your day by doing activities that you enjoy—this can help you get out of your head and into your life.
Try distracting yourself with a fun, enjoyable activity. Make sure that you're focusing on the activity itself, and not on any negative thoughts in your head.
Cut off all contact. That's it. Don't give them any reason to feed into their obsessions. Cut them off on social media and block their number. Don't hesitate to take...
Many emails come with an "Unsubscribe" option somewhere in the message. Clicking on "Unsubscribe" may result in your being removed from their mailing list.
Practice mindfulness meditation every day for a minimum of 15-20 minutes. Recognize when the obsessive thinking is happening and redirect your focus instead on what you're doing in the moment.
You probably should devise a plan to make yourself consciously aware of such outward dialogue. There are many cognitive approaches and orientations that can prove effective with this. So, focus...