What is the best way to sleep when u have degenerative disc. On ur back or belly or on ur side. And should I put a pillow under my back or my foot?

How are you comfort. how are you comfortable. Back or side may be the best, other than that what fits your comfort. Where is the degenerative disc? Neck, thoracic vertebrae, lumbar area? You need to discuss with your physician about your symptoms. Despite having the disc this may not be symptomatic and your symptoms may be something else. Check it out.