Consider the possibility of an end-plate fracture in your lumbar spine vertebrae as well. End plate fracture is commonly caused by a compressive trauma such as landing on buttock. This injury affects the interface between your lumbar spinal disc and the bone of the vertebrae. Often, x-rays and sometimes Wikipedia reference-linkMRI would not detect this injury if it was not looked out for. At 14 weeks post injury without significant relief from your symptoms, I agree with robertcqu that organising a CT or MRI (if not done) would be appropriate.