This sounds to me like LBP syndrome, or Low Back Pain syndrome related to strained intervatebral disk or spinus muscles. However it could also be a sliped disc syndrome, where you have burst or comperssed the cusion between your vertabrae.
There is another remote possiblity of kidney infection.
Both potentialiteis requie an exmaination by a phycisian and a exray inorder to properly differintiate.
My recommedation is to sleep on a firm flat surface, drink plenty of fluids, and to seek an appointment with a phycisian. I recommend Ibuprofen or Motrin for pain according to the instructions on the bottle.
In the case that your condition might be your kidnees, since I cannot prescribe to you, I will recommend some homeopathic approaches for keeping your kidney's active until you have visited the phycisian. Asparagus is a natural diuretic, so you should eat asparagus with your dinner meal each night. With breakfast drink cranberry juice, cranberry juice is a very mild analgesic for the kidneys and promotes kidney function. Avoid oranges and grapefruits and spinach as they tend to produce renal calculi.
Follow your doctors instructions once you have seen him or her.