Hi.
Thank for your query and an elucidate history.
Read and understood your detailed history, visiting different countries, exposed to different atmosphere and so on.
Since your problems are related to the throat and the upper chest, this is called upper
respiratory tract infection. Since the airways are in continuity, the infection can traverse up and down the tract.
Anxiety does add to the respiratory problems directly.
I would advise you the following:
Take a rest of few days at home in the ambiance of your home.
Take steam inhalations as it helps to loosen the phlegm and allows easy
expectoration.
Take medicine as per the Doctor has given over and follow the instructions well.
Take multivitamins as they work as anti-oxidants helping in faster recovery.,