Well that is odd, I felt real dizzy and sick, weak, tired and all around like crap for a few days but it went a way after while.
If you plan on staing on a LC plan you really my want to start a journal here and list the foods you eat everyday. Maybe it is something you are eating. Somethings have hidden carbs and sugars that could be throwing you off. Did they check your thyroid? I know you said every test but just checking.
Well good luck with what ever you decide. I hope it all works out. If you want list what you have been eating.