What Is The Treatment For Sore Throat,nasal Congestion And Phlegm?

Hi, I am a 34 year old, male and have been suffering with recurrent sore throats now for around 2 years. Initially I was put on a 3 month low dose of Antibitoics which seems to keep the sore throats at bay for the most part. But once the three month course was complete, my symptoms returned. I had my tonsils removed last year, but the sore throats are still reoccurring. More often then not I feel discomfort on the left side of my throat when I yawn or sing, this generally escalates into a sore throat more often then not. My voice becomes husky and hoarse, and I constantly need to clear my throat. Also have a sensation of something stuck in my throat when I try and swallow.That said there can be days when I am symptom free. Also the sore throats are responsive to antibiotics. Generally I would need to take antibiotics to relieve the symptoms as nothing else works, At the moment I have a sore throat, nasal congestion and phlegm in my chest going on 2 weeks ( have not sought treatment for this occurrence yet) I'm also asthmatic and take Seretide and Ventolin most days. Your thoughts would be greatly appreciated.