Look, I'm not an expert, but I certainly can relate to this. It simply could be anxiety. Oh, it's a terrible thing, but I currently had a problem you're currently having not too long ago. All I did was try to take it easy and it took some of the symptoms away over time. So just try to take it easy, cut-off the eating for awhile (Unless you've been doing that, because that can explain the out of breath feeling and achieness), and do the things you love to get your mind off being sick. If you can't do any, just sleep away.