Gestational Diabetes

So I just left my 34 week appt (I'm 34+3) and was told by my Dr that I didn't pass my second 3hr glucose test that I took last Friday... I'm so bummed, I now have to switch to a high risk Dr and clinic to be monitored better....I've always been obese and never had any health problems, I know that has nothing to do with getting GD as our hormones are different during pregnancy, but I'm so upset with myself...I do eat a lot of sugar which is a main reason why I'm overweight to begin with...I didn't have this with my other 2 kids and I'm not sure what to expect, so if anyone can give me some insight I would appreciate it!!!