Chronic Back Pain

In an effort to discover why I am having so much pain in my back I figure I can try blogging/journalling it and learning as much I can about my body and maybe why its happening and how I can cure it. I have been looking into Knowledge Therapy and the idea that stress could be the cause rather than a physical reason. I have been having severe back pain for about 3 weeks now. I have no idea how people deal with it for months, years and decades. I often woke up with the pain - generally in my middle back, in between my shoulder blades. I have a shower which only relieves the pain ever so slightly. Sometimes the pain dissipates or lightens but gets worse as the day becomes night. I am not sleeping very well though I am very tired. Its causing me to think about dying - cos surely if I was a horse I'd be shot. I have no other reason to think of suicide so its concerning.
I don't recall having an injury but I do believe that the body is meant to repair and recover. I do not think the medical profession will  (or is not capable to) help me.
I have looked at the way I sleep. I am sleeping on a queen size bed with my husband and youngest child. I usually feed bub once or twice a night. He accepts if I say no more. I tried sleeping on another bed but it was still uncomfortable in the morning.
At my husband's advice I have tried stretching more. A friend told me it is related to my posture so I have been more aware of that. Yet the pain has become worse. Today I bend over or down and I cry "Far Out" Its unbelieveable excruciating pain and agony. I hate feeling this useless. If this is psychosomatic then I can have hope. I pray that this will be over and I can get back to be a Mama who is not yelling and doesn't get upset when they want a hug because it hurts.