Hi. I had GDM with my son. It was an overwhelming feeling at diagnosis, but hang in there and you'll learn amazing new things and get through fine.
You must change your diet. There is no option really for you baby. Sustained high blood glucose is what can cause birth defects or fetal death. But there are many ways to do this so don't get scared! Your docs will work on nutrition with you, but one they don't talk to pregnant women about much is exercise. They assume pregnant women won't do anything of the sort. It is kinda funny in retrospect, but that doubt by healthcare providers was what motivated me.
I was walking to an appointment. They told me I had to come in to learn insulin because despite my extremely diligent diet, my glucose was still too high (normal, btw. Don't think you have 'failed' if this happens. The placenta just becomes more and more insulin resistant thru pregnancy to give more nutrients to the growing baby. Us GDM women's placentas just go on overdrive). I was just due for checking my sugar after breakfast and... Totally normal!!! I asked the nurse and she says 'oh ya, walking lowers your blood glucose, but we don't expect you to excercise regularly...'. I was so insensed I asked to delay the insulin for a week to see how I could do.
After *every* meal I got up and walked for at least 15 minutes. By the end that was all I could do, plus it was January in Boston.
I stayed off insulin for two more months, only taking it the last four weeks of pregnancy. I know now how important the insulin was for my baby but I also know I did everying I could to be as healthy as possible.
So walk if you can. And hang in there, test you glucose, read labels. You will learn more about the American food system and how badly we eat in these next few months than in your life so far. And that is a gift you can give to your child and family. You will have to know it now because we are at higher risk for developing type 2 for the rest of our lives. Stay ahead of the statistic, stay healthy!
If you want to talk more, email me anytime. I work at Joslin Diabetes Center now in part because of my experience. ____@____.com