ACCUTANE,--- did you take it in your past?
The nasal/sinus irrigation system called Hydropulse might be of help for you. Just do a search for it online to get more info on it. I have chronic Post Nasal Drip due to sinusitis and I have bought one of them recently, and it has improved it reasonably well, and as you suffer from just sinus infection you could benefit from this more as it cleans your sinuses really well. Also this product is not as expensive in the US as it is here in UK. :)
Good luck,
Avine
It is not rare to have continued sinus infections following surgery, although this is not the usual course. Postoperative swelling can keep the opening of the sinuses closed and therefore the infection persists. However, if the surgery is successful, the swelling should resolve and the openings of the sinuses should open and allow normal drainage. In view of how you feel right now about what has happened in the last month, it is a good idea to seek another opinion.