What the hell is wrong with me?

I am a 17 year old high school student. I am 6'1 and I weigh between 270> and <280 pounds, and I am a male. Despite my weight, I stay active. The problem that has been plaguing me for about six weeks now is a chronic cough. Before the onset of the cough, I was spitting out mucous for about two-three weeks. Then came the cough. For the first two-three weeks, the cough was very dry. Now, within the last week, the symptoms have become significantly worse. I now suffer from debilitating coughing spells that have reached a new record today at over a minute. They also take literally ALL the energy out of my body. I also now suffer from the chills. Today, I went to the nurse, but she said that my temperature was 99 degrees and that there was nothing in my lungs. Despite her conclusion, I don't think this is the flu. I have had the flu, but no flu has ever felt like this before. So what do you think I have?

P.S. Here's some additional info:

1. My calf muscles in my right leg have been tensing up on me today.

2. During my Sophomore year of high school, my school was subject to a Tuberculosis outbreak. I was not found to be infected at the time.