Left head and neck pain. Or laying down.

I have had constant left and neck pain for weeks now. I have been hospitalized but after a week was released partially by my choice because I missed my children. Regretting my decision. While in the hospital they tried a nerve block. They found I do have compressed arteries on my left side but they don't seem to think that is the cause to my problem. Although that needs to be handled later. I am on several pain killers and it eases the pain as long as I am laying down but if I am active something as simple as laying down the pain intensifies. It's a throbbing yet sharp and almost electric shock feeling starting at the neck and shoots up. Like previously said activity makes it much worse seems as though anything within intisified blood flow. I want to know what could be wrong I don't want to constantly be on pain killers or laying down.