As far as i remember I had to go for wholemeal pasta and bread and brown rice as far as carbs were concerned, and still less than a third of a plateful, possibly even less than that, I can’t remember.
I could basically have as much protein, fat and non-sweet veg as I wanted. Easy on the fruit because of the fruit sugars, the safest way was to eat them only as part of a meal. Baked potatoes are more sugary than boiled for some reason.
Anything sweet could only be eaten in very small quantities and as part of a meal so that it got sort of absorbed in with the rest of the meal.
You can get little snack bags of ready cooked chicken chunks in supermarkets, I should think they’d be ok as they’re just protein (& additives & salt & water). Possibly things like samosas, because they have a very thin crust and just meat and/or veg on the inside. Normal pie crusts would probably be too thick.
Cereals were hard, I got some expensive muesli from a health food shop in the end that was specifically designed to have a low glycemic index. Eggs, or indeed a full English, are good for breakfast with some wholemeal toast if you have the time to cook.
You may need to spend a long time looking around the supermarket reading labels.
Good luck and sympathy, it is a total pain in the arse but it’s not your fault and you can only do your best. It may even get you into better habits (though I went straight back to the biscuit tin asap, you might do better!). It’ll be such a relief when your baby is born! 