Hello Dry cough with congestion , running nose , sneezing , fever with chills from last 3 months may be due to these reasons , these include. 1 Asthmatic allergic bronchitis , when such case visit my clinic I advise them to take monteleukast+ levoceterizine once or twice in day. But if symptoms are associated with breathlessness take monteukast+ bambuterole one or two in day. 2 Tuberculosis , as cough is from last 3 months so sometimes dry cough also present in tuberculosis particularly PTB is also associated with allergy . Diagnosis can be confirmed by X ray chest and sputum for A F B . blood for C B C , E S R ( IF 100 mm highly suggestive of PTB or any other chronic infection). 3 Allergic rhinitis is another most common cause of of such symptoms due to inflammation of nasal lining membrane . Please consult a physician and get his opinion.