<human>: Whenever I go to sleep I usually lay on one side. Through the night the pain will usually wake me up and I will roll over to my other side. I then repeat this several times. The worst and most lasting pain comes from laying on my back. It is now thirty minutes after I woke up and I am still in quite a bit of pain. 

I have some theories as to what causes this but I'm not sure and not everything matches up. I have mild fibromyalgia but the pain is in my lumbar area and not in my joints so I don't think that's what's affecting me. I am severely overweight/obese, could that be what's causing this?

Summarize the given text in a few sentences.
<bot>: I have serious lumbar pain whichever way I sleep. What is causing this and how can I fix it? Thanks guys.