Why am I always hungry?

It could be WHAT your eating, and not how much you eat it. The number one cause for desire for food (besides food addictives) is the human body's necessity for certain vitamins and minerals; for example a man might normally drink a gl of milk every day and then when he stops, he suddenly finds an urge for cheese or yogurt, which have sufficient supplies of the initial mineral cut out of his diet, calcium. Try taking an every-day vitamin/mineral supplement, this could stop the excessive eating, and if thiis problem continues i suggest you return to the doctor's office, as your body may have a conition known as hypoglycemia, the opposite of diabetes, in which teh body produces too MUCH insulin. As for your lethargy around 3 p.m. i would guess it to be nothing more than a natural bodily reaction. Whenever we consume too much food, our body usually chooses to digest it all at once for fear of converting it all to fat, so all of its energy generally goes to digestion, which leaves the person lethargic and physically exhausted, which could also be the cause of your breathing difficulty and "anxiety". I hope this helps! Best of luck!