Anyone with gestational diabetes?

I just got a call from my doctors office saying that I failed my 1 hour test. I had GD with my last pregnancy, but don't remember how it made me feel physically. Well, about 10 minutes ago, I suddenly felt dizzy and like I was about to pass out. But I didn't. All i had today so far(as of 11:50am) was turkey and egg white sandwich and a vanilla sweet cream cold brew from Starbucks. Does this sound gd related or did I not eat enough? I have to do the 3 hour test next week. Thanks!