Calm your mind on a regular basis. You humans tend to overthink too much, worry too much, feel too much, see too much, strategize too much. This tires out your mind, your body, your immune system, and your spirit. You need to give your mind a rest on a daily basis.
It may sound counterintuitive, but you need to do this first thing after you wake up. Your mind is already in a quieted state from sleep. It has not had a chance to get to a full revolution of thoughts and worries. Yes, you may awaken with worry on your mind and you may have marinated all night long in worry, but your unconsciousness diluted it and it weakened. When you awaken, whether you have worry or overthinking on your mind or not, it is in a weakened state.
Awaken and go directly into a meditative state. Focus on a sound or on a guided meditation that concentrates on your situation of worry, anxiety, overthinking, etc. Spend at least 10-15 minutes in this state. It will ground you. It will keep the momentum at a slower pace. It will make you see things in a different and not so dire perspective. It will calm your respiratory and circulatory systems.
You can turn to meditation at any time during the day – when you feel overwhelmed by anxiety or overproduction of thoughts – simply focus on your breath. Close your eyes and focus on the rhythm of your breath until you feel a calmness overcome you. Focus on its rhythmic pattern of deep inhalation in, holding for three moments, then slow deep exhalation out. Repeat as often as necessary. Amen.