Hi..
Welcome to HEALTHCARE MAGIC..
I have gone through your query and can understand your concerns..
As per your complain thick phlegm in throat if it seems like coming from the back of nose can be due to
sinus infection or sinusitis while
acid reflux can be one of the cause and as you do not have acid reflux it can be due to
Laryngopharyngeal reflux or silent reflux in which there is
throat irritation and phlegm formation and no heart burn..
The yellow coating in mouth seems to be due to yeast infection known as
Oral Thrush and swelling can be due to inflammation caused secondary to infection..
Any confirmation can be done only after a thorough clinical evaluation and investigation as required depending upon the cause suspected so that treatment can be planned accordingly..
As of now you can take antacids, do steam inhalations and gargle with Nystatin mouth wash..
Drink plenty of water..
Hope this information helps..
Thanks and regards.
Dr. Honey Nandwani Arora.