Firstly know that diabetes is not your fault. It can happen to anyone, based on your physiology, not what you eat.
So now, you will need to pay attention to food and I suggest you eat lower carb. It is not true that your baby needs carbs to grow, it needs your blood sugar to be stable for optimal growth.
If diet alone cannot manage this, they will put you on insulin. that is not a bad thing, and not as scarey as it sounds, because this will allow you to have a healthy baby.
Hugs. Please ask questions. I've had 2 diabetic pregnancies and have 2 wonderful daughters as a result.