Breathing worse after septoplasty, turbinate reduction and adnoidectmy

The only way to know what is blocking your breathing is to have your nose examined.  Whistling sometimes can indicate the presence of a perforation, or hole, in your septum.  This can result from septoplasty surgery.  Allergies may be a factor as well.

The whistling can be a sign of a perforation in the septum.  You need to come in and be examined. Difficulty breathing can be caused by swelling of the
soft tissues on turbinates usually from allergies, airway obstruction from a
deviated septum, fractured nasal bones, polyps or large bony prominences from
the turbinates. Soft tissue swelling can
be treated by reducing exposure to allergens, and medications such as antihistamines
and steroids. The other listed problems
need to be addressed surgically. Best of luck, Dr. Michael OmidiAn in-person exam with a
board-certified plastic surgeon is the best way to assess your needs and
provide true medical advice. The response to the question does not
constitute a doctor patient relationship or formal advice.

I would discuss these concerns with my surgeon.  He can look into your nose to determine possible causes such as adhesions, debris or any other causes.  it is important to have you nose re-examinded.  A secondary procedure may benefit you.