Chronic lower back pain.. What should I do? Nothing has helped!

Patient: Hi, I have chronic lower back pain. I can’t stand or sit for more than 15 to 20 minutes without making th e pain worse. I have been put through the ringer with tests. I have had 2 MRI’s, x-rays, injections, numrous blood tests, physical therapy, aqua therapy. Nothing has taken the pain away. Due to knee problems I already sleep with a pillow between my legs. I’m 25 yrs old, 5’7″, and 165 lbs. My pain level is always at an 8 to 10. It’s been 5 months… What should I do?