Can you tell me more about the efficacy, safety, and legality of Cannabidiol (CBD) oil?

I recently heard about CBD oil - that it can be effective for chronic pain and anxiety, both of which I've struggled with (and seen many specialists about) for years. But when I went looking for more information, I couldn't find many resources that looked like they came from legitimate, trustworthy sources. Can you shed some light on the subject?


How can I prevent and relieve neck pain?

When I worry/stress out, I find the muscles on one side of my neck (usually the right side) begin to tighten up to the point of acute pain. On occasion, the pain reaches from the back of my ear, down my neck (the most painful point), through my shoulder, down the arm, and in extreme cases to the tips of my fingers. Two questions:

1. How do I stop this?
2. How do I relieve the pain when it occurs?

I'm currently suffering from one of these neck aches, and can't turn my head, so I'd really appreciate your response.