Oh hun, I know how much a VBAC means to you & I hope that whether or not you need to go on insulin does not have an affect on it. You'll need to speak to the hospital where you are going to be birthing at and find out what their & the OBS policies are. I am miffed that you haven't been able to get on top of this but like the op's have said, sounds like diet & exercise aren't going to be able to control your GD diagnosis.