This is going to sound so stupid, but did any of these docs check you for hernias? My dad and my brother both suffered from them. My dad's was abdominal and HUGE. He just ignored it for years until the pain made him do something about it. My brothers was sub inguial and he described pain like yours. Took the docs months to pin point what the pain was from and then to find out exactly where is was. It was kinda hiding down there. (p.m. me if I am being too vage. It's a more personal topic than I think you would like me to get into on a public forum.)