OP I agree with earlier posters that your problem is not calorie intake but blood sugar control.
I cook for a family member who is diabetic, and has been for the past 10 years or so.
They are very disciplined, but at the same time really enjoy their food. Based on their experience, there's no need to feel deprived. They 'took control' of their situation and actively wanted to make their blood sugar as good as possible. This meant that I -as the family cook - had to learn quite a bit, but it was interesting. Their GP says that their blood sugar control now is 'admirable'. They have no need of medication, just regular blood tests. If - as I surmise from your posts - you are at home, then you have even better opportunities than most to cook nice but diabetic-friendly food.
Personally, I find Michael Moseley's presentational style VASTLY MORE THAN irritating, but his books on very low carb diets are accessible and important. I suggest you read them and perhaps follow some of his recipes.
But one other thing that has been overlooked on this thread - except by a few posters - is the importance of 'glycaemic index' - that is, the rate at which carbs are absorbed into the bloodstream. To put it crudely, the more slowly and gradually that is, the better. Carb absorption is influenced by fibre and by fats. So the carbs from white toast will be absorbed into the bloodstream much much faster ( and disadvantageously- blood sugar spike etc as discussed by previous posters) than those from wholemeal and seedy bread plus (for example) home-made hmmus or raw mashed avocado. See here, just as an example, there are many others: https://www.betterhealth.vic.gov.au/health/healthyliving/carbohydrates-and-the-glycaemic-index
If, as you say, you cannot eat gluten then that's another point to help you along your way. Ideally, you hav to avoid many /most refined grains. But other 'grains' are available. Just for example, buckwheat flour (gluten free) makes excellent and traditional pancakes. Just have a look at various wholefood sellers, such as - simply taken as an example - buywholefoodsonline.co.uk
If it helps, here is what the person I cook for has/will be eating today:
breakfast: fruit salad made of (a few) blueberries and a small (unpeeled) pear plus a small nectarine, all chopped and seved with probably a tablespoon or two of cream. No sugar. A home baked (by me) smallish roll of wholemeal flour plus a LOT of sunflower seeds (and, in the baking, added olive oil and yeast and salt and water, of course). Plus a scraping of butter and a scraping of high-fruit blueberry jam.
Weak black coffee.
lunch: fried bacon pus a few butterbeans stirred into the oil/fat from the beans, served with a big (am not going to say MN 'massive') salad. It comprised one little gem lettuce, shredded, five mini plum tomatoes plus about 2 inches of cucumber, chopped, plus 3 pink radishes, plus about a third of a red pepper plus a gherkin. It would have contained olives, as well, but I forgot them, plus spring onions, but I had run out. Simple extra virgin olive oil and vinegar dressing.
Three mini - about palm of hand-sized - buckwheat pancakes, plus a scraping of butter and jam, as above. (Pancakes = wholemeal buckwheat flour, egg, plain yoghurt (just because we had some left over), water and yeast. Mix very well until consistency of double cream. Leave several hours to rise. Fry in as little oil as you can get away with, flipping each pancake over once base is crispy and bubbles have risen to the surface. Delicious.)
Weak tea - no milk - but slice of lemon
5 pm: cup of weak tea - no milk, again - and two (home made) chocolate nut clusters. Just 70% or more dark chocolate melted then a surprising amount of chopped/flaked nuts stirred into - as much as the melted chocoate will absorb.. A good heaped teaspoon = a cluster.
7.30 pm - still to be cooked - three cold roasted high meat content sausages (the other three in the pack were eaten roasted yesterday) plus chopped onion, chopped red pepper, chopped tomato and some herbs and a bit of chopped garlic, all cooked gently in olive oil. Combine (slicing the sausages into chunks) , adding a bit of water and if liked a squeeze or two of tomato puree. Simmer gently - perhaps covering the whole lot with a lid to prevent evaporation. Keep an eye on them and add enough water to stop sticking and leave a modicum of sauce. Sprinkle with soy sauce/ground black pepper before serving, if liked,
Serve with a small quantity of new potatoes (fewer carbs per oz than old ones) - allow perhaps three SMALL hen's eggs sized ones or four smaller ones per portion. Plus an awful lot of greenery - a mix of broccoli, cauliflower, kale, spring cabbage, french/runner beans etc etc . Could add separately fried mushrooms as well if liked.