Pain in back of head behind right ear

This pain comes on in the snap of your finger. I can't figure out just what trigers it.It starts in the back right side of my head and neck and goes into the bone behind my right ear causing my ear to hurt and goes over into my head in the front and all over the right side of my head. And at night when I lye down to go to sleep and I lay on my back the back of my neck starts hurting and then there it goes so fast it is on then. I have to get up and sleep in the recliner in an upward position so I'm not lying on my neck. But that is not the only time I get the head ach I can be just sitting or driving and it suddenly will come and it comes so hard and so fast it is full blown before I know it is happening. I get this every day and I would love for someone to tell me what I should do. Or what they think is happening. Thanks Brenda...