I agree, call your doc.
That said, what I had to do was eat frequent smaller meals that were protein rich with a smaller carb.
For example, a cheese stick and nine triscuits for a snack.
Pick high fiber choices, plenty of protein, lots of veggies and greens, not so much potatoes or starch, and don't be lured by sugar free pop or desserts. They are NOT wise calorie choices and not good for you or baby.
All the walking will help burn calories too. Do not forget to snack, but always a carb AND a protein.
It's not the same as regular diabetes. Your body isn't functioning right, and it's not really about what you are eating.
Diet didn't help for me, and I was rigid about it. I finally needed insulin.
NOT everyone does, though. But I want to encourage you that no matter if you do or not, you will be ok.
I felt so empowered by being able to administer the insulin myself, after being so frustrated that correct eating didn't help my symptoms.
They finally told me it wasn't my fault, that GD isn't food related. WHEW.
I had felt like such a failure up till then.
All this to say, when you get back, and you have your appts., and you learn all you are to do, don't get overwhelmed.
It's not what you are doing, it's what your body is doing. And the moms I know are very strong and smart, and can do just about anything if it protects their kids!