Severe lower back pain, over year, lay down on hard surface and it cracks without moving a muscle, pain lessens significantly, must do daily, 23yr fm?

One year?: Time to get examined and xrays. I would advise orthopedic evaluation.

Ligament need repair: When the same part of a back always 'cracks' w/ just relaxing on a floor it means that when standing, sitting, bending, etc. the ligaments which should 'check' or stop excessive motion like forward flexion are likely injured or overstretched.Osteopathic manipulation w/ prolotherapy can often heal the ligament so it can do its job.In my experience, after a year, ligaments rarely heal on their own.