I "HATE " the word diet! The first 3 letters spell DIE!
It's not a diet, its' a lifestyle change!
First, you have to get your mind in gear. Then, you have to be willing to take the good days with the bad ones, experiment, trial and error.
What works for me, may not work for you.
When you stumble and fall, as we all do sometimes, don't beat yourself up.
Give yourself credit for your good choices, tell yourself you are worth it, learn from the stumbles and carry on!