Strange Back Pain

Hi All. Please can you help with this one. For many years now i get this weird upper back pain when im hungry. I have been told that it is acid like heartburn causing the pain. I try and not miss a meal , alot of the time if i do it doesnt effect me. But the last couple of days have been agony, the pain gets so bad i try to eat but just start getting sick and cant hold anything down. Any ideas?