Oh, been there, dieted my way up to 212lbs, couldn't fit into the t-shirt
Can I say something that'll sound like a load of new-age nonsense?
Every time I failed, I was trying to apply a diet to my life from outside myself, to fix myself. This time, I've changed my lifestyle in accordance with who I am on the INSIDE. I'm not doing it TO love myself, I'm doing it BECAUSE I do
It's hard to explain properly, but... I'm sure this is why it's working this time, and I'm still happy because I'm not trying to shape myself into something I'm not any more.
One thing's for sure: if you always do what you always did, you'll always get what you always got. I used to panic diet, telling me willpower would be enough to MAKE me do it. It wasn't, as proved by my regains.
Start off thinking about what you love
Activities, foods, your mindset, everything. How do you approach problems, say, at work? Find something that fits your temperament, and do not panic! Bad decisions are made whilst under stress. Don't subscribe to the "no excuses" or "every little helps" ways of thinking (for example) if that's not who you are. If you're more a "I don't want exercise to feel like exercise", then take dancing lessons instead of a gym membership, or something. If you can practice moderation, use that. If you find it too hard, another approach might work better.
Long winded, I know, sorry... It's just the one thing I never GOT about it before. Use as many of your personal strengths as you can, and account for your weaknesses, instead of just taking a diet out of the box and expecting it to fit. I did that for tooooo long
Wherever you end up, I wish you the best of luck