Mental training works very well, as it trains nervous responses. You kill fear by training your struggle against fear, by visualizing it, by disengaging yourself, by dominating and mocking it and by giving it incongruous and stupid shapes.
To concentrate means to be here and now, thinking about one thing: what you are looking at and what you are hearing. To concentrate means to think about what you are doing right now and not about what you will be doing later. Concentration is love.
The ability to consciously do nothing is the ability to tighten the spring. It is the ability to focus efforts into a point and, having reached critical mass, to create a new universe with an explosion.
The lack of growth and movement leads to the release of energy, which can be accumulated by stretching, like a bowstring or spring. The stored energy can be used for explosive growth. To do this, you need to have a specific goal and avoid energy leakage. Fear and joy are radiators to release excess energy. In addition, the energy can leave through parasitic actions that are kind of calming. Any activity, including thoughts, leads to a drain of energy.
All the problems in your life started when you weren't breathing right. You think you need to breathe deeply, but, in fact, you need to breathe with your stomach. One should be restrained in breathing.