You seem to have developed a perforation of the septum, which is a recognised complication of septoplasty, and would have been explained to you before surgery. The whistling sound could be due to that. But it should not cause any other significant complications. As far as the throat infections are concerned, the perforation itself is not a cause. If you have coexisting sinusitis, or gastro-esophageal reflux, it may cause recurrent sore throats, and should be looked into.