Nuts are not necessarily a nutritionally bad choice in a lot of contexts, they are high in fiber and vitamins and minerals and healthy fats, and are relatively filling, but are also high in fat and very calorie dense, 5+kcal/gram so in the context of someone struggling to get their calorie intake down, adding small volumes of super calorie dense foods is usually a good way to add extra calories for not a lot of extra satiation. And it is just way too easy to eat a lot of nuts and get in a huge number of calories. I added some nuts into my diet not that long ago but only measured out in 20 gram quantities per day. Sounds more like she failed to tailor her advice to your particular needs, which is essentially her job.
I always found fairly low calorie density but high protein snacks to be most effective for hunger control, like low fat high protein yogurt, very lean meat, low calorie fruit, salad/raw veges etc, but I am on a diet with 40-50% of calories from protein and most dietitians would be a bit horrified by that.
The science on artificial sweeteners is so complex I do not think anyone fully understands it, there is so much contradictory info out there that interpreting it is almost impossible. Maybe they mess with satiation or post ingestive hormonal responses but far from definite.
One of the most useful things I did was input my diet into chat gpt, as it is very repetitive to minimise gut symptoms I could just use 1 day to represent it fairly accurately, but if the diet was more normal you could make a diary of everything for a week including weights and shove that into chatgpt in research/scholar mode and get it to analyse calories, fat, protein, carbs, fiber etc. I found it pretty informative, it is the kind of thing a dietitian could do, but chatgpt is going to be quicker and possibly more accurate, and I found chatgpt could give sensible dietary advice, at least the way I used it .
Just saw the above post after finishing writing this with at least 2 things the same included.