There's a breathing trick that soldiers use in combat zones. If they can somehow fall asleep when in danger, with bombs and shit going off all around, then I reckoned it would work for me. And it does!
it goes like this:
Breathe in THROUGH YOUR NOSE for a count of 4
Breathe out THROUGH YOUR MOUTH for a count of 8
Repeat, repeat.
While doing this, also try to relax your body as you breathe out. And pause any thoughts/worrying. For me, for some reason, it helps to imagine (with eyes closed) that I am staring at a spot roughly in the centre of my forehead.
If you catch yourself going over endless conversations you've had/might have, fretting over things you've said or done or might say or do or must say or do soon, just gently shelve them.
Just focus on the counting and the breathing pattern.
This kind of slow, controlled breathing directly activates the parasympathetic nervous system (the body's 'rest and digest' mode). Your heart rate slows, muscles relax, cortisol drops, and brain shifts out of threat‑monitoring and into a state where sleep becomes possible.
Honestly, it really does.