For me personally it seems to make it impossible to get to sleep. Which makes me tired, and less resistant to rambling trains of thought. Repeat ad infinitum.
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.
I don't usually have this issue, but when I do I find just focusing on breath, meditation style, helps. As soon as you notice yourself thinking, acknowledge the thought gently, and then let it go. At least for me (with a bit of practice) this can head off any thoughts before they can get started, and eventually allow things to quiet down.
Also, acknowledging the fact that, since I'm in bed trying to sleep, I can't act on these thoughts right now anyway, so I don't really need to have them right now (and trusting that if it's important, they will probably come up again at a more useful moment).
