Hi Ela, welcome to the Forum and congratulations on your pregnancy. I had gestational diabetes 20 years ago and was on low doses of insulin to stop the baby getting too big, the baby grows but the lungs and other internal organs don't mature so quickly, so it is really important to get your levels under control. The advice has changed since I had gestation diabetes and if I were you I would definitely cut out some of the carbohydrates in your diet ie. bread, potatoes, rice, pasta, cake, biscuits anything really with flour in it, althoug you may be able to tolerate some, but you will need to test to see whether they spike you or not. This will help lower your blood sugar quite a bit, eat plenty of leafy vegetables, salad, any type of meat or fish, eggs as long as they are well cooked. Some fruit is also high in carbohydrate, but you can eat berries in moderation. You could snack on full fat yoghurt with berries, nuts, avocado pear. I think you have to be careful of certain cheeses and mayonnaise and soft eggs as there is a risk of salmonella, but check with your midwife as this may also have changed.
Once my daughter was born (3 weeks early), my diabetes disappeard immediatly after the birth, but I have since recently been diagnosed with Type 2. My daughter suffered no ill effects and is now a healthy 20 year old.
Good luck with your pregnancy, I am sure it will go well.
Hope this helps.
Marilyn x