I get that feeling of being unable to breathe on occassion, and it is not a pleasant thing to experience.
Since you are going through such a stressful time, your adrenals might also be involved - the more reason to up your water intake and maybe include some form of clorophyll - chlorella maybe? (I take Chloroxygen drops 18 /day [I got them at Whole Foods market])
"ChlorOxygen® Chlorophyll Concentrate
(extracted from English Stinging Nettle Fresh). Use for low red blood cell count, fatigue, shortness of breath, high altitude sickness, or heavy menstrual flow. Intestinal deodorizer.
Dose: Each 36-drop dose delivers 100 milligrams of Chlorophyll Concentrate™. Take 20-35 drops (before meals) three times a day."
Please do try to eat lighter fare, maybe lots of fresh juices, to help your body use the energy to handle the stress your'e experiencing.