Persistent Post Nasal Drip and Sore Throat

[vintage14]

In the beginning of September, shortly after moving into a new apartment, I was very sick with what appeared to be strep, although a culture came back negative. I had fever, sore throat, white coating in my throat, sinus pressure, and headache. My doctor put me on amoxicillin which slowly helped. A few days after I finished the ten day treatment, my post-nasal drip and sore throat came back. It lasted 2-3 days, then went away. A few days later, it was back, and worse. I went to the doctor again, who said it looked like I had a throat abcess (abscess). He gave me omnicef and medrol pack. The sore throat and post-nasal drip got better after those meds, and again, a few days after I finished them, it was back. It progressively got worse, and my ears began to ache as well. I went to a new doctor, who told me that this was likely allergies (related to the new neighborhood or new apartment).  She mentioned 'cobblestoning' in my throat and said my ears were sore from sneezing.  She prescribed me flonase and told me to take over the counter claritin. I've been on flonase for about a week with no change. The sore throat and post-nasal drip are persistent and very painful. It particularly worse in the morning, and I have been taking advil for the pain.  This has been going on for so long, and I'm a grad student that really can't afford to be sick. If anyone could shed some light on what this might be, I'd really appreciate it!

[National Jewish]

One common cause for all of these symptoms is a sinus infection, even after the antibiotics.  I would suggest a CT scan of the sinuses as a first step in making the diagnosis.