"I have been brushed off by the doctor"

I have been feeling ill and disorientated for over two months. The doctor at at the medical centre has told me that I have sinusitis and has given me medication for it but it hasn’t worked and I would like a referral to see a neurologist. I feel I have been brushed off by the doctor. I don’t like bothering them but I am concerned about my health and don’t feel listened to. It is also very difficult to get a timely appointment, no matter when I ring or go in to ask for one.