What Causes Dizziness, Nausea And Pressure In Head?

Good morning. I have been having this problem for the past months and feel it is getting worse. I have had vertigo on and off since I was 22, I am now 30. My symptoms are dizziness, naseau, pressure in my head and neck, and also feel a bit of numbness on the back of my head. No headache just pressure. I was driving the other day and had to pull over because I was to dizzy to keep goig. It comes all of a sudden and i have to lay down to sleep it off. But when I awake it still feels like the room is moving. Help!