I am sorry that the first thing you read was the Potato Diet. That was just somthing some people were playing around with. It is not the primal lifestyle by a long shot. It was people screwing around with a "hack." Many people got the results they were looking for, but it is not the primal way of eating. Please spend some time reading the site, Click on the "Start Here" button and get a good idea of what primal eating is all about. And read the book. Also, take a look at the Whole30 website and that is a very clean and strict version of primal that might be good for you. Seriously, read the "start here" information and then give it another go. Don't despair!
Also remember, Primal is not a "diet;" it is a way of eating. Not everyone eats this way to lose weight, but to eat real food to feel healthier and better without grains and processed "food."