What Causes Pressure On Right Side Of Head And Neck?

Hi,I am a 34 year old male, weighing 80kg and 5ft 8inches in height. For the past one week I have an uncomfortable pressure in the right side of my head that also runs down the right side of my neck, only in the evenings, and it gets more uncomfortable when lying down at night. I consulted an ENT specialist who said he sees nothing wrong with my ears,throat and nose. what could be the problem? I have always has phlegm. The ENT specialist gave me rhinomer (nasal spray), vibrocil (microdoser) and Aerius 5mg (desloratadine), but theres no relief.