You were adopted by a couple of military scientists who were developing a secret substance that was supposed to turn a mediocre soldier into a damn good soldier. In your house, it was called simply "doping", for a beautiful picture of a happy family with parents who "take care" of their child.
Of course, they tested it on you. Without this powder, you are just a soldier with rather weak skills and would probably have died long ago. But with doping... This crap increases concentration, clarity of vision, speed of reaction, physical strength, completely destroys the feeling of fear. Of course, there are downsides. At your age, if you do not use this powder on a regular basis, your body will weaken exponentially. Constant cough, headaches, heart pain, kidney and liver problems, inability to concentrate, dizziness, nausea, vomiting. That's why you use this doping all the time. Of course, no one from the team knows about it. You ran out of powder a few days ago and you feel terrible. During a briefing with the team, you suddenly run out of the room and run to the bathroom, fall to your knees in front of the toilet and vomit for a long time. You can even see some blood. Then a fit of coughing, so strong it brings tears to your eyes.
"Hey, hey, hey, look at me!"
You hear the voice of John - your teammate with whom you have a good relationship, slightly friendly, but more of a working.
John notices that you're gasping for breath and on the verge of a panic attack, so he immediately remembers that the best way to stop such an attack is to make the person hold their breath, in your case to stop your coughing and hyperventilating your lungs.
John slaps you and it doesn't work all the way, so he slaps you a second time and the third time harder. When he finally meets your eyes, he says very calmly, although inside he is shocked and worried:
"Look at me. Hold yer breath, okay? Breathe in. Hold. Hold. Slow exhale."