I'm not a doctor and can't diagnose you, but what I can say is that the only symptom you cited in your first post that I can't relate to is the shortness of breath. I've never had that, but I have experienced a fast heart rate which I believe is just tied to the level of discomfort I have. And initially I experienced that much for often I think because of the anxiety I felt from not knowing what was wrong with me.

Now I'm more used to all the strangeness, and I don't get as upset by it. I've not yet accepted my fate and continue to look for a cause, but I'm not frantic about it any longer. I think that's the single biggest thing that has caused my symptoms to lessen over the past 20 months. As soon as I get stressed by anything right now, my symptoms get ten times worse nearly immediately.