It can take a while.....if you keep doing what your doing salt is not somthing to be rinsing with it can irritate the area more. keep it clean and let it heal if you feel like there is scar tissue in there and want it removed later on you can but for now quit rinsing with salt water
the same thing happened to one of my friends from high school it took 2 weeks for the swelling to go down but to this day she still has a small but noticeable knot from scar tissue .... but she didnt take care of it like you are doing just keep it clean and hopfully it will go down all the way
dont use mouth wash as it could irritate it go to your doctors and you will probly get a cream or sent to hospital to see (ent)ears nose throat doctors