Exercise is the best medicine. It clears the mind, dissipates doubts, and frees up anxieties. It also instills a certain level of confidence not found when sedentary. It helps with presence of mind; the ability to think in the present and not get caught up with doubts, fears, and "what if's".
But exercise alone isn't enough to solve all of our internal problems. Exercise alone can still be used to procrastinate and be irresponsible, ignoring and putting off important problems.
Another core of the best medicine a human can get is a certain type of social interaction. Not just any social interaction will do. It's incredibly effective for us to interact with other people whom we have a shared struggle, whatever that may be, and to discuss it. That discussion can be forced, but often it's best if it comes up organically. The topic can be brought up and that isn't detrimental, but it comes through natural discussion that it can really be discussed in a meaningful manner. This may take time. It most definitely re