Best product I have used for respiratory infection is Echinacea Goldenseal by Paradise Herbs. It is very potent and effective. I usually buy it from iHerb.com. I'm on the east coast so I can't get it in any stores locally. But, it really works. It even helped a coworker of mine who has had chronic bronchitis for years, and she is also type 1 diabetic, with no side effects. It has a few support herbs like isatis, honeysuckle and forsythia flower. Perhaps it could help you get over the hump.