Gestational diabetes. Advice, anyone?

So, I got the call today that I failed my 2 hour GTT. The first blood draw was fine, but the one hour and two hour draws were too high for doc's liking by just a smidge, so they're referring me to a diabetes counselor.

It's borderline enough that I hope diet alone should be enough to handle it. I was already eating fairly healthy, or at least I thought I was! I wonder if it may have come on because I'm getting an extra boost of hormones from weekly P17 shots, plus I was at an increased risk for it already due to lupus.

Either way, I'd love to hear from anyone who had gestational diabetes. My main concern right now is that I'm trying to avoid a c-section and I'm worried my risk is going to go up for one. As I mentioned before, I'm already on shots to stave off preterm labor, so this has been a pretty rocky pregnancy to begin with.