I don't have any professional background yet in nutrition other than what I was required to learn to get my personal training certification, but I will say one of the things they hammered hard was carb cutting really isn't a long term solution. The body needs carbs, especially when you are exercising, it is where most of your energy comes from. Carbs have gotten a bad rap because of refined flour and fried foods. Potatoes are actually not horrible for you if they aren't covered in oil, butter, cheese, salt, etc. I was tracking my macros for a while when I was cutting weight this past month and my intake was about 60% carbs, 15-20% fat, and 20-25% protein. I lost 7+lbs in a month and a half. My carbs mostly came from brown rice, potatoes, fruits and veggies. High protein diets can do more harm than good, but I know that they can help jump start weight loss. If used for an extended period of time though, it can cause stress to the kidneys, requires more water for digestion, and if it is lots of red meat there is an increases risk for heart disease. (That being said my dad has heart disease and was put on a high protein diet by a medical professional, they had him drinking a ton of water and slowly started introducing more carbs. His results at the time were good. He was being monitored, exercising, and had appointments every few weeks with his doc.)
I get your attachment to your meat, even as someone that doesn't eat meat, there are just things that we as humans find comfort in and have no desire to abandon. Like you said, portion control is where that factors in. The US tends to over eat in the meat and dairy departments, if you look at the numbers from 20, 30, 50 years ago the consumption of these products have skyrocketed. In the attempts to produce more meat and dairy, corners have been cut. The chicken breast your eat today is not the same as yesteryear as an example. The chickens grow faster, and while the birds are getting bigger they're also more fatty and not eating the same nutritional profile they used to. Same thing can be said about grass-fed beef, it tends to be leaner than a corn chewin' cow. So my recommendation when you are eating meat is to look for local farmers to purchase from, and if that isn't possible splurge for the grass fed stuff at the supermarket. It will be leaner and have a better nutritional make up than a factory farmed counterpart.
I also swap things out for healthier options and try to reduce consumption of stuff overtime. Like chickpea based pasta noodles instead of wheat, or using avocado instead of mayo. I weaned myself off most sweets and adding sugar to coffee. Little changes start to add up over time. And your cravings will subside too. I used to be a cookie monster, now i rarely get that craving (but if you put them in front of me all bets are off).
I am starting a nutrition certification soon, and when I have more of a legit knowledge base I'd be happy to help ya further, but if you think this is something beyond nutrition it might be worth while to talk to a doctor. Sometimes there are imbalances that need to be addressed by a professional.