I am 42 and have had lower back pain for two weeks now. I have have had back pain before but this isnt the same. It is a sharp pain. It wont go away.?

See a doctor. Most back pain is benign but rarely there can be serious causes. Therefore it is important for you to see your family doctor to get checked out. If you do not have a doctor, try to find a local medical clinic or go to an emergency room at a hospital near you.
Be seen. It is likely a musculoskeletal problem, but needs to be evaluated.