I doubt that all these symptoms stem from a sinus infection alone.
The discomfort in the neck and behind the ear can be due to irritation/inflammation of the occipital nerve(neuralgia) which exits from the back of the neck and runs up into the scalp behind the ear. It is treated with Tylenol (acetaminophen) and, if you can take them, antiinflammatories like Advil or Aleve. A middle ear infection is also possible.
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