What Causes Nausea And Severe Pain In The Upper Back?

So the other day I was not feeling well, felt nauseated and laid down then the feeling went away. later on I was standing in the kitchen serving dinner and all of a sudden I got severe pain that almost dropped me to the ground in my mid to upper back, mostly in the center but evenly spread off from my spine on both sides of my back. It was difficult to breathe (due to pain) and hurt worse when I take in deep breaths or suck my stomach in. It does not feel like it is muscle as touching, pushing on, and rubbing does not make it worse or better, and it is almost like you can t actually touch where the pain is. The pain feels deep in and hurts inside a lot worse with breathing, sucking in stomach, certain movements – however pain will quit if I bend over and lean forward, or certain ways that I twist or turn.. The worst pain is from laying or sitting and raising up, or sucking my tummy in. Ibuprofen is not very helpful and I am on the third day of feeling like this. I turn at night and am awakened by the pain, which is not getting any better or worse. The pain is way above my kidney area and my heartbeat, and bowel and bladder are all normal with no changes. Appetite is still good, and it does not get any better or worse with eating or drinking. I am just concerned because I have no idea what it could possibly be - no injury or use of my back to make the pain start. I literally was standing at a counter sprinkling cheese on a plate when it hit.