gestational diabetes/ glyburide 2.5 mg

I just got a call from my dr that I m going to have to start taking glyburide 2x a day.. once in the morning and once at night.. I just started checking my sugars last week... my fasting number, then 2 hours after breakfast/lunch/dinner.. all my numbers during the day have been perfect but I can't get my fasting number down.. it's stead 120-123, although yesterday it was 118 and today 117.... someone please give me some kind of advice! I'm a mess. I'm sad, & I'm angry at myself!