Sore throat, headaches, sharp pain on back of neck & persistent pain (3/10) at base of left ear only. Recently treated 4 bronchitis. Causes?

New infection. Sounds like you have an upper respiratory infection. An infection of the throat by a virus can cause pain to radiate up into the ear and vise versa. Try taking some ibuprofen, drink lots of fluids and rest. if you develop shortness of breath or high fever then you should see your doctor again. If your throat is red, swollen and has white patches on it, then you should see your doctor.
Viral illness. More than likely your symptoms are due to a viral illness illness.