Our bodies are unique. What works for one person will not work for another, which is why some of us try a fad diet and it works, and for others it doesn't. You're not doing anything wrong. Each one of us is different due to biochemical individuality from our varying genetic makeup. You simply need to figure out what your body responds to and needs.
Have you ever taken a serious look at your diet and the key foods you're consuming? Counting calories, eat this, not that, gluten free, paleo, etc., all of these ways to eat become overwhelming and complicated. Food and eating shouldn't be difficult, yet, because we've introduced processed foods and taken away many of the vitamins, minerals and enzymes needed to best fuel our bodies, we're left to scramble for solutions.
Whole foods. Good quality meat. Organic fruits and vegetables. These are the foods our bodies crave. These are the foods our bodies need to thrive and survive. Foods found in majority of diets today lack the essentials. It's vital we reintroduce the foods this planet offers us to heal our bodies, inside and out, as well as our mental health and longevity.