Simple test: what were your thoughts and emotions 5 minutes ago? 1 hour ago? since this morning? and how were you breathing (slowly with good posture or rapidly)? If your brain is constantly circling thoughts with no cool-down with bad posture it's guaranteed you will have physical problems.
For me the cure was a combination of:
- Slow breathing exercises
- Mindfulness (to learn to listen to the body and emotions, an to be aware and able to "control" thoughts). No mysticism bullshit, just having a brain and body at rest and present.
- Stoic philosophy : not worrying with things not in my control, not being affected by outcomes (e.g. objectively did my best and the boss/client is not happy? That's fine for me)
- Strength training
- Nutrition
- Financial security (I know I'm lucky but that doesn't change the point)
- Edit: "reconnecting with nature": again no mysticism, just outdoor walks, gardening, and taking the time to observe and appreciate while being fine doing nothing
The best I could describe my default state now is as being relatively at peace, with no negative thoughts circling, slowly breathing with good posture (that I can maintain while coding long hours for example). I'm still of anxious nature and still worry about the future, but only on the time period I will allow it (and not as a the permanent background noise). YMMV obviously.