Health problem

I read in a book that Japanese children are taught about the Hara Center(two inches below and behind the navel)right from childhood.:It is called Dan tien in China. I have a problem of overthinking as a result of which I my doing gets affected adversely and my doing in general is poor . Focusing on the hara center does make one thoughtless but I want to improve as much as possible for confidence in my work and life in general. I would appreciate any practical guidance on the issue- books in English on hara center or its exercises

We aren�ft really taught about it in school – I�fve been taught in yoga school (in my gym) about the importance of centering our body on that location. Maybe you could find some yoga lessons near you?
https://en.wikipedia.org/wiki/Dantian
Hope you find some calm.

Useful Hara Breathing Exercise, hope that helps.
This two-part breathing exercise helps you set your hara, center yourself, and maintain expansive
energy at the same time. It�fs great for settling down and manifesting calm gravitas before entering a
challenging situation. Start by getting a feel for setting the hara (a), then do the inhale #1/exhale #1 (c
and d) a few times, then add inhale #2/exhale #2 (e and f) and alternate: https://docsbay.net/hara-breathing-exercise