Cold sores are caused by the herpes simplex virus. They are a sign that your immune system isn't keeping the virus under control well enough. They can be easily treated if you use L-Lysine:
umm.edu/health/medical/altmed/supplement/lysine I know when I was doing the elimination diet for food allergies, I had to be free of all possible irritants for 4 weeks before I could start reintroducing foods to see how I would react. I would assume it will take that long as well for you - although that doesn't mean that you won't have improved breathing before that.
And, yes, I would suggest that you hold off on the Paragone. Your body is under stress as evidenced by the cold sore. At least give it another week, unless your doc has said otherwise.