Treatment For Knee Pain And Coughing Fit?

I m a 69 yr. old male in excellent health until the past 2 yrs. Last year I had a bout with acid-reflux and had to go on a regimen of Prilosec. No problems since. A week ago, however, I came down with a sudden onset of severe coughing, sore throat, congestion, and filming on both eyes. We had a snow storm here, so I wasn t able to get in to see a specialist. I drove myself to the ER. They did blood work, throat swabs and a CAT scan and determined that I was suffering from some sort of viral infection. They gave me a prescription for hydrocodone/acetaminophen. My throat was so swollen it looked like a had a goiter. I couldn t take solids for a few days and could barely tolerate liquids the pain was so intense. Happily, the pain has since abated and I m able to be up and about. I m less congested, the eye filming has abated, and I m able to eat normally, though my taste buds as still a bit off kilter. Last night, however, I awoke at 1:15 am with severe pain in my left knee in the region of the patella, I also had a rather prolonged coughing fit. I tried alternating ice pacs and heat wraps to my knee and was able to diminish the pain enough to get another couple hours sleep. I m limping and can t do full extension or bending of my left leg without inducing knee pain. My wife, a medical writer, thinks my immune system is chasing the virus around my system and it s settled in my knee. What do you think? What should I do to alleviate the pain at night? I d taken cough medicine and hydrocodone when I went to bed last night. They didn t prevent the episode I ve detailed. Thanks for any advice you can give me.