I have been smelling exhaust fumes everywhere i go. it is so strong that it gives me a headache even nauseous. what can this be? how does it go away?

Dysosmia: That is the term used for an abnormal smell that isn't actually present. This could indicate that there is a nasal or sinus problem. However, this could indicate that there is a neurologic issue that needs to be evaluated. You would be best to start with your primary doctor and then consider seeing an ENT and neurologist.

Neurological?: Would see primary md to work up. Possible seizure ? Possible ENT issue.