Actually, sinus infection, if anything should give you a reduction in smell acuity.
I've not heard that it causes paradoxical hyperosmia. But what can do that is an irritative stimulus in a place known as the "olfactory groove"..which is just above the cribriform plate in the head. What kinds of smells you'e been having? If your new found talent persists I'd have a neurologist look first before EN