My Dr. also first suspected a "feeding" problem with my first SW CAH’er...it turned out to SW CAH, first time my Dr. had seen it,  my Ped’s office now does a complete metabolic screen on all their patients.  It is a very difficult time when a baby is not doing well.  My CAH’er was born at 8 12oz and got down to 6 14oz when he was 3 weeks old-  he looked terrible!

Good luck to you.