Hi.. Welcome to HEALTHCARE MAGIC.. I have gone through your query and can understand your concerns.. As per your complain it seems that you have a Sinus Infection or Sinusitis leading to congestion in nose as the sinuses drains through nose.. It does not seems to be oy due to allergic reaction.. Therefore taking only Fexofenadine that is an anti-allergic is not alone going to relieve the symptoms.. I would suggest you to consult an Otolaryngologist and get evaluated and a thorough clinical evaluation and investigations like PNS VIEW or MRI Scan of the sinuses can help in diagnosis and treatment can be done accordingly.. You can be advised to take a course of antibiotics like Augmentin, anti inflammatory painkiller like Ibuprofen, decongestant like Phenylephrine.. Do saline nasal irrigation as it loosen mucous and ease in its drainage.. You can do steam inhalation and use a humidifier in your room.. You can take decongestant nasal spray containing Xylometazoline.. Avoid chilled foods.. Continue taking Fexofenadine as advised to you and no need to exceed the dose.. Hope this information helps.. Thanks and regards. Dr.Honey Nandwani Arora.