(Barring you being a metabolic mutant. If you have tried counting calories and it didn't work for you, then please ignore this post; weight loss is a lot more complicated than how I am about to describe it here.)

Permanent weight loss is possible and feasible; however it will probably require constant effort to maintain.

For example, count your daily caloric intake on myfitnesspal.com (my username is shokke, if you wish to use the social aspect of it too). Eat at a caloric deficit (TDEE minus ~500) until desired weight is attained, then continue counting calories and eat at maintenance (TDEE) indefinitely. If you stop counting calories you will very likely regain that weight.

This requires you to count calories for the rest of your life, or at least until you no longer care about your weight. Or we develop a better method of weight control.