Yes, try an app – I do manage with MyFitnessPal, which I find helpful – it shows you all sorts of interesting things about the makeup of the food.
If you can keep your grams of carbs under 50g per day, that does help with weight loss.
Re nuts – just to let you know, it’s not the carbs which are the problem but the calories. For instance 25g of mixed nuts (which is not really a lot,probably c 20 – 22 nuts) is 166 calories, 1 carb, 16g fat. The fat isn’t a problem, on BSD full fat is good and it fills you up. But if you’ve only got 800 calories to play with, do use nuts in moderation!!
🙂