Take an SSRI. That can stabilize the neurotransmitter responsible for the chest discomfort leading to that need for a deep breath and the following air hunger and even panic. But in an emergency, go someplace by yourself and sing. Sing something that makes you happy or you're just feeling and the action changes your breathing pattern 🙂 When it happens before bed, another really effective thing to stop the air hunger is something I learned from my college psychologist. You start with your feet and tense the muscles, then enjoy the feeling when you relax them. Then you move up and do the same thing with each calf, then the thighs, belly and so on... it's a deep relaxation trick and it works! Your agonal breathing can be averted this way along with a bit of melatonin : ) But for long term, find the med that stabilizes the chemical imbalance responsible. For me, it was the SSRI.