Hello Welcome in H.C.M. I have gone through your query regarding sore in right nostril with green mucus. Your symptoms and clinical history favors nasal infection it may or may not be associated with sinusitis , nasal polyp , deviated septum or allergy. To manage it you should go for- 1- C.T. Scan of paranasal sinuses. 2- Culture and sensitivity of nasal discharge. 3- Blood - CBC, ESR, blood sugar (F & PP) 4- If nasal cavity has granulation than biopsy. Beside this a thorough examination of ENT is must to get physical findings and their co-relation with inferences of above investigations will disclose the facts for diagnosis. Once the diagnosis is established treatment may be plan accordingly. Regards.