Don't give up!! If you keep trying, it will come. I have weighed as much as 240 lbs and as little as 125 pounds in the last four years. I am a 5' 9" 43 old man who weighs 194. I have tried everything and succeeded an failed many times.
This is not a diet, but a way of life. It makes so much sense to me. Candidly, if you absorb less fat and watch your caloric intake, I cannot believe it won't work.
I have been successful in a low fat diet. This actually lets you have more fat than most low fat diets simply because you are not absorbing as much.
Please don't give up. You will figure it out. It really helps if you keep a detailed journal.
Clint