Back Pain only when i sleep and first few hours after awakening??

Every night, around 2 or 3 am i wake up with back pain ( go to bed around 11pm).. it's between my shoulder blades about half way down my back and when i inhale deep, i also get a sharp pain in that exact same place...this has been going on for alittle over a year now, but the pain from inhaling is new for me...Ive replaced my mattress 3 times, sleep with 2 pillows propped up behind me and i have to sleep on my back. if i sleep on my side, i wake up with the pain again. I can not lay flat on the bed with just one pillow under my head because it hurts my lower back, im always having to be slightly inclined enough so that my body is making a small "V" instead of a stragiht line when lying down.. i wake up at 6am and by 7am the pain is gone??...anyone know what this could be??? the only solution ive found is to do pilates or yoga before bed, but even then it's only a temporary solution until i can fall asleep...thank u

[capegirlnoshoes]

I'm not a physio (you should probly see one of those) so I don't really know, but for what it's worth, I have pain like that, between the shoulderblades, down the spine, and my physio said it's stiff vertebral joints.  She fixes it by rubbing on either side of and pushing on each vertebrae and getting me to stretch.