I have had throbbing in the back of my head only when laying down, neck stiffness , extreme tiredness and some dizziness for the past week or so- the doctor said I had an ear infection and gave me antibiotics- last night was the first night I was taking them- I found that I would yawn at night, and then, phlegm would come up from my throat... is that normal? the phlegm was a yellow ish color- what is that?