Practice “Box Breathing” to stay calm and focused in tense situations.
Navy SEALs use this technique to stay calm and focused in tense situations. It’s simple and effective. Even breathing elicits a calming parasympathetic response while allowing you to remain alert and able to deal with the situation. If you lengthen the exhalations you will elicit a stronger parasympathetic response which will deepen the relaxation and be more conducive to sleep.
Inhale to a count of 4, hold for 4, exhale for 4, and hold for 4.