Tonsils

I have never been one to have throat problems. I have had strep once, but my throat has been extremely sore for the past 2 days. I went to the doctor, and they tested me for the flu, strep, and mono. All came up negative. She told me that I'm fine, it would go away on its on, and prescribed me some ibuprofen, but I am having a hard time believing that there is not something more going on. I have no appetite, I can't drink anything, I am keeping major headaches, and I can't stay asleep.