You can go for wholemeal, brown rice, healthier options. Cut down on carbs but increase protein. If you want chocolate, find sugar free chocolate or plain dark chocolate. NTUC has a few sugar free chocolate under the brand belgian and sugarless. You can try finding that.
Take non-sugared drinks or use sweeteners.
You can also consider joining the fb group singapore gestational diabetes support group. All the mummies have GD before or now and they share a lot of tips to manage GD.