That is one symptom I notice on the days that I am very stressed out. I have experienced this several times this year, and the days that I feel this way, I notice that I hold my breath too much, which causes me to feel out of breath (air hunger). This is a very annoying symptom, but I find that decreasing stress as much as possible, exercising, and finding something to help distract yourself helps.

This sounds like Sleep Apnea. I would recommend thinking about having a Sleep Study done, if possible. Especially if you are often tired during the day, have snoring, or relatives have it. I have Panic Disorder & Obstructive Sleep Apnea. Waking up gasping for breath is a very significant sign of Sleep Apnea. That was one of the key signs that I had before testing was done. I have been awoken by nocturnal panic attacks and I also wake up gasping due to sleep apnea - for me personally those two things feel very different.