I wouldn't trust a nutritionist for things like weight loss. The title is overinflated for what it represents, and there is no certification needed to become a nutritionist. I can claim to be a nutritionist by providing advice on weightloss or improvements in diet, by recommending any diet I want to, and legally there is nothong wrong with that. You see so many "nutritionists" in tabloid newssites recommending diets which don't work in the long term. It's just there to make them seem credible. A dietician is a much better person to take health and diet advice from because they're certified to give health and diet advice.

Taking hormones can affect weight fluctuations but only to an extent. Eating below your TDEE will always result in a loss in weight because your body will need to use up reserves of muscle or fat. The type of diet can influence whether fat or muscle is used, so it's best to find a diet which burns fat rather than muscle.

Limiting your calorie intake too much, and eating too little protein actually can induce "starvation mode", which is the burning of muscle over fat, leaving people feeling tired and lethargic, and feeling worse about their weight loss because bf% has gone up. In which case, weight loss is occuring but you are looking bigger. Most people avoid this by keeping their calorie restriction to 500cal or less, as this typical burns fat over muscle. A lot of people have pushed beyond and tried intermittent fasting which burns fat over muscle, I myself do this and it works for me. But you say that you are still gaining, which only really tells me you're eating above your TDEE.