I Have A Pain In This ONE Nerve In My

I have a pain in this ONE nerve in my head. The pain feels "sharp" and "shocking". Level pain averages about a 5, but lately its been getting up to a 7-8. The pain lasts for about 2-5 seconds, and probably happens over 50 times a day. Its worse when i'm in the car or at work. It does not disrupt my sleep. Seems like the pain isn't there. How do i relieve it? how is it caused?