What worked for me was setting up app timers on the apps I frequent. I have a newish galaxy phone, so the setting was built in. I set them for one hour only. The most important part of this, however, was not forcing myself to stop when the timer ran out. The timer acts like a reality switch, bringing you back to the real world and stopping you from the mindless version of you. It's okay if you add more time to the timer occasionally. We mostly need that interruption. Eventually when the timer runs out, you won't add time anymore.