How Can I Resolve Persistent Phlegm Since A Fever Despite Using Nasal Sprays And Tablets?

Hi,i got a fever in September 2021 and from then till now contant phlegm has been forming in my throat every single day and it does not go away no matter what i do, i have even took medicated nasal sprays and tablets for this matter and it does not get fixed,please let me know how i can fix this problem as it causes a discomfort in my daily life.