Diabetic

So my OB called me Thursday night to tell me that my glucose came back and I do have gestational diabetes and I have to meet with a nutritionist so they can teach me how to take my blood sugar level and all of that... Now I am super nervous because my next appointment with my OB is in a week and I occasionally feel really dizzy, lightheaded, and have terrible hot flashes. I try to watch what I eat and everything but I've passed out before and now I know I have gestational diabetes I get even more nervous... Is there anything I can do when I feel like this I drink water and I've been having a light snack on me... But it's not working at all...