Meditation comes in various forms, one of which that could be useful is focused attention meditation.

Basically you focus all your attention on one thing and do everything you can to keep your attention on that thing until the timer goes off.

An example could be like a dime. You out a dime on the table and look at it. And you try to focus all your attention on it. Your attention goes elsewhere, but you keep bringing it back.

It’s very difficult but it can be improved.

What I found is that after I did that kind of meditation for 5 minutes a day, for a few weeks, it was easier to (a) notice when I was thinking about something specific, and (b) just stop thinking about it, and refocus on something else.

In other words it improved my metacognition and my attentional control.

Those are two attributes that can empower a person to better handle and avoid obsession or rumination problems.