Welcome to HCM, I have gone through you query and understood your concerns, I think you have a severe allergic process I kindly suggest to take other antihistamine instead zyrtec, some zyrtec side effects include dry mouth and pharyngitis anyway your symptoms are not improving it s very important to humidify the air and maintain a free allergens environment (smoke, spray, perfumes, dust, chemical odors or any other inhalants) drink enough water and breathing slowly in warm steam hot bowl of water, sometimes during the cough crisis just an environment change can relieve the symptoms. Please kindly rate if my advise has been helpful Wishing you a good health Dr Tania Portelles-Driggs