I am having severe pain in my upper and lower abdomen on the left side, that gos right through my back. i feel nautious and don't eat much.?

See a doctor: Your symptoms could be any number of things but to be sure you should see a doctor and get fully evaluated. You may have a kidney infection or kidney stone. It is even possible to have appendicitis although not likely. You may have an intestinal problem like a hernia or infection. Treatment for all of these are very different. Best to go to urgent care or emergency department asap.