Hi and welcome.

I lost all my weight on South Beach so I have a very soft spot for it in my heart. I believe the advice "don't worry about calories" is very helpful in the beginning when you are re-learning how to eat, and maybe learning for the first time in your life how to eat without grains and sugar. Personally, I found that if I counted carbs and kept them to under 50g per day, the calories took care of themselves. Once you're comfortable with this new way of eating you may or may not feel a need to include counting calories. I didn't count calories until I'd been maintaining my weight loss for many months and noticed a few pounds creeping back on. In the beginning you might be surprised to find that it is not very easy to overeat on nothing but protein and green leafy vegetables because they are so incredibly satiating without the added starches and sugars. It's the rice and pasta and bread, etc. that make us hungry.

I understand your concern about not relying on your body to send real hunger signals (I used to be the same way before low carbing). My suggestion would be to start out with three moderate meals of protein and veg + two small snacks (like, e.g. a stick of string cheese or slice of ham) and see how that goes. Use it as your baseline. If you don't feel satiated increase the protein and veg in your meals. I would not increase the size of the snacks - that can become a very slippery slope. On the other hand, if you are feeling full, I'd cut out the snacks first. If still full, then go for smaller portions of protein. . The first most essential step is to cut back on the carbs and eliminate those grains and sugars as much as you possibly can - and of course alcohol in the beginning.

The very best of luck to you, you can do this!