I Have Had A Very Painful Sore Throat For Over

I have had a very painful sore throat for over a month. It hurt to swallow. The first 2-3 weeks I also had a cough that was jarring. It was a very deep cough, couldn't sleep, some drainage and mucous. I am fatigued most of the day which is very unusual for me. I am normally very active, rarely ill and when I rarely get "whatever is going around" with everyone else, I have a very light case of whatever that is. I originally thought this was allergies, I have some allergic reactions when pollens are extremely bad. I have had no fever. Did lab yesterday to see if WBC's were elevated or if I were anemic to explain some of this. Everything was fine. So what kind of virus lasts this long? The sore throat improved after a light course of steroids to cool the inflammation. Two days later, it was back as before just not quite as bad and I don't have the deep cough like I did. I am so perplexed.