If you're having severe back pain (or any unusual or severe symptom) you're better off going to a doctor as soon as possible. First, severe pain is never something that you should just live with, and it may be able to be treated. Second, it's possible that whatever is causing your severe pain could lead to worse problems or be a symptom of something serious. (I don't mean to scare you, but it's important to rule things like that out sooner rather than later.)