What is wrong if there's severe pain in the left buttock's that wraps around the outside of the left hip and it leaves a burning sensation on outside of hip er x-rays said they didn't see anything?

It could be pain in the Gluteus Medius muscle which is on the lateral side of the body, hence the hip. It could be lymphatic as well since there are several lymph nodes in the buttocks region that are very deep. It could be a nerve distribution issue in your body depending on size and post injury state.