A cough that persists this long could be due to asthma but the persistence, in a person who had no cough before, suggests the diagnosis of pertussis, commonly called whooping cough
. You should probably see a lung specialist to be examined, have a chest
x-ray and pulmonary function tests, to get to the bottom of this. Your symptoms do not suggest anxiety, as the primary diagnosis, but you may be experiencing anxiety because this illness has not cleared-up.