"Obsessive licking can be due to a few things. Nausea, a show of submission, liking the taste of something or a metabolic deficiency are all possible causes. I suspect that it may be nausea in this case. It sounds like you may be seeing a reverse sneeze. It commonly occurs due to nasal irritation. It looks much worse than it actually is. Check the video below to make sure that is what you are seeing. If related to congestion, post nasal drip may be making her nauseated. This actually happens to one of my dogs often. I typically let her outside, and she starts chewing on a lot of grass. It will either settle their stomach or make them vomit, which in turn makes them feel better. Usually, you can give Benedryl to help with the signs. If she is around 15-30lbs, you can give a 25mg Benedryl safety every 8-12 hours. See if that helps. Please let me know if you have any other questions. Hope this helps."
Take no credit for all that.