Have had this issue sometimes, specially when ruminating about a discussion or whatever. What i often do in those cases is going into visual mode. For me I imagine having big long wings and catching the wind from some high mountain descending flying slowly, trying to surround the mountain and checking the views. It's something soothing and takes the attention away from the internal monologe. Though you can fall back to it and when you notice go back to visual. I also note that there is like two visual modes, one less defined, more controlled by my will, and one more realistic and crowded with details mostly out of my control.