Is Tummy Tuck Ever Considered A Medical Necessity?

Eleven years ago, my big, beautiful twin boy and girl were delivered by C-section.  My baby girl weighed eight lbs and my boy weighed six and a half lbs.  At eight months pregnant my belly measured four-and-a-half feet around!  Ever since their birth, I have had a fatigued feeling and discomfort in my lower abdominal muscles.  This spring, I was really trying to get in shape, and exercised harder than I ever have, but awoke one night at the end of May with a dull, throbbing pain in my right groin.  I have all the symptoms of a femoral (or possibly an inguinal) hernia on both my left and right sides.  On October 16, an ultrasound of the femoral triangle showed no signs of a hernia on either side.  I have consulted two surgeons who cannot feel hernias.  And my ob/gyn says that I do not have a problem with my female organs.  The ultrasound he ordered was normal as well.  The only thing I do know for sure, is that the plastic surgeon I consulted has told me that I have diastasis recti (there is at least a three-finger gap in my lower abdominal muscles).  She feels that "in theory" a tummy tuck could possibly relieve the source of my pain.  I have tried to avoid having a CT scan, not wanting to take the risks involved, and feeling that it will not show the source of my pain either.  What else could I do to find out what is wrong?  Standing and walking cause the pain to worsen.  Lying on my back with an ice pack on the area of pain helps.  However, the thing that sets off this throbbing pain the most often, is when I cross my legs (as if something is getting pinched).  It is the very worst at night when I'm lying on my side.  The "pinched" feeling sets off throbbing pain that lasts for hours.  Should I see a specialist?  What can I do to locate the cause of this pain?  The plastic surgeon has told me that my abdominal muscles are coming in at an angle rather than straight down, and that could be a possible cause of this pain.  Do you agree?  Is it possible to prove to my insurance company that abdominoplasty is a medical necessity?