Bad Smell in Nose 2 Months After Setoplasty?

I had a septoplasty, tonsillectomy, and tissue removed from my inner nasal cavity and sinuses about 2 months ago. All of a sudden, I'm starting to notice a severely disgusting smell that's located inside my nose and frequently, when mucus seeps down to my throat, I can smell it coming from there as well. That smell is the only thing I can smell. What can be the cause of this? I called my doctor and he just prescribed antibiotics over the phone. What else can it be? Why does it smell so bad?