Having major back problems?

Ok so I go to sleep every night in a very comfy bed in a very comfy position and in about 5 hours later i wake up wife excruciating back pain. This happens almost every night and it forces me to get up, walk around bait, so sit on the couch down stairs and wait for it to go away before I can even think about going back to sleep. I have tried OTC pain relievers and nothing touches it, I am also a bit over weight, but not thinking that my weight would really play a part in it seeing I am laying down. Maybe it does, who knows. Anyways any ideas or if you have had this problem as well please your ideas are welcome.