What is the best position to sleep in when u have degenerative disc in the lower back. And does it gets better over time?

Fetal. Fetal position: laying on side Erik pillows between arms and legs, hips and elbows flexed.
Degenerative dz. Sleep in the lateral position to reduce direct pressure on the spine. DJD of the spine does not get better unless you strengthen the para-spinal muscles that support the spine. Ask your PCP for lumbar strengthening excercises.