I Have A Really Bad Sore Throat, It Makes Me

I have a really bad sore throat, it makes me cough a lot and when I cough, I coughed out yellow or kind of yellowish green a little thick mucous out. I went to HEB clinic to get checked out and she prescribe me azelastine I think this just treats stuffed up nose. Not the itchy sore throat and cough. I've had this for 4 days now. When I went to her it wasn't so bad and I wasn't coughing the yellowish green mucous . But when I left the clinic two days ago it got worse. I stopped the azelastine because it was making me sleepy and I'm not sure if these treats the symptoms I'm having. Do you think I need an antibiotic? I'm scared I don't want it to get worse?