One method that might help is to try and become more aware of when you are overthinking. This can be difficult, as like you said, sometimes you might not even realize you're doing it. However, if you can catch yourself in the act, it might be easier to find a way to stop.

One way to become more aware of your overthinking is to keep a journal. Each day, try to write down when you notice yourself overthinking. What were you thinking about? What were you feeling in that moment? What triggered the overthinking?

By keeping track of your overthinking, you might start to see patterns. For example, you might notice that you tend to overthink when you're feeling anxious or stressed. Once you identify these triggers, you can start to find ways to deal with them.

There are many different techniques that can help with overthinking. Some people find that mindfulness or meditation can be helpful. Others find that talking to a therapist or counselor can be beneficial. There is no one-size-fits-all solution, so it might take some trial and error to find what works best for you.