Dear Patient, lets look at your symptoms Shoulder pain left= severe Strain of voice= thyroid ruled out, ENT surgeon has already seen you. Light headedness= Now non of these symptoms have coherence with each other, and this is the reason that they say its in your head. I feel you need to take analgesics if you feel pain, and see how much relief you get from it. also take a lot of fluids, and regular exercise. the most important part is to come out of disease psyche. Hope that helps Thanks