Abdominal/back Pain With Burning And Pressure. I Vomit And Have Nausea During Pain

I have burning and pain that starts in my abdomen and radiates to the back.There is pressure like labor contractions. I vomit and have nausea during pain. It is difficult to breathe in or out during an attack.I m on no fat diet, mostly soup, veggies, and fruit. I have had several since early January. I went to the hospital thinking gallstones, but ultrasound came out good. They are now treating me for ulcers, I m taking Prilosec and still having pains with vomiting and nausea. I ve dropped ten pounds because most food makes me sick on the stomach. The pain varies in intensity and length. Can you help?