I have severe pain above my right buttock on my lower back only hurts when i walk. is this a disk or sciatica?

Many possibilities: It could be caused by many different conditions: sacroiliac joint dysfunction, myofascial gluteal pain, disc disruption, 'sciatica' from a compressed nerve in your back, 'sciatica' from a compressed nerve in your buttock muscle (piriformis syndrome), referred pain from hip or lumbar spinal arthritis or a compression fracture of a vertebra. I'd suggest you see a physician to find the source.

Sciatica: Pain in the distribution as you suggested describes the pattern of the nerve that travels in the leg called the sciatic nerve. The sciatic nerve is not the cause of the pain source, it is the result of an irritated nerve typically in the lumbar spine (low back) which are caused by herniated disks, spinal stenosis or degenerative disc disease requiring further evaluation by a spine specialist.