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Your doctor is right, because of sinusitis
there is swelling at the nasal end of the Eustachian tube causing blockage sensation in the ear. Secondly, when the infected sinus secretions trickle down into the throat, they carry the infected material from the sinus, which in turn leads to inflammation of the pharyngeal wall. Once the inflammation sets in there is appearance of the glands behind the angle of the jaw.
All these are reactions to the actual process of infection. I would suggest you to use saline nasal spray
, do steam inhalation and drink plenty of warm water. And also, take a course of good antibiotics and mucolytics.