Sore throat cough yellow phlegm. Tell.

Happy Mahashivratri to all doctors . I have dry cough for last 4 days . Which cause later sore throat throat pain . And when I cough yellow bulgum came out which is hard and comes through nose while sneezing. I m doing saline water gargle for morning and night . I am a teacher so whenever I try to speak for few minutes cough start and throat is badly sore. No table to talk . In silence not much cough when talk or speak dry coughing start . I m taking liptuss dry syrup for last  two days for  two times and I started amoxyclav  tab yesterday night. How long should use . Antibiotics take one time or two time. Syrup should be stopped or not . For throat pain taking zerodol sp. But sore throat and cough not reducing I have attached pic of throat and tell. Thank u .