I've been the same weight for like 15 years now. Like, exactly the same. Not somewhere around something, no, exactly. And then when I do something that makes me lose some weight, like my long and plentiful walks, I regain weight until that same point again in no-time. It's a good thing though, my BMI is basically perfect.
But sorry I don't mean to brag.
I hope your diet works out, I wish you good luck. All the advice I could give is just to eat natural; pretty much everything that comes in a wrapping or container has been processed. Which you can eat, but mix it up with enough fresh stuff. You need meat, but you don't need meat every day. Cook in olive oil. Use tomatoes, red and yellow food is usually bad, unless it's red because of the tomatoes. Water is best, tea is good too as that is just warm water with plant extracts. Juice is mixed, good on one hand (fresh juice anyway) because of all the minerals and vitamins, but bad on the other because of the naturally occurring sugars in fruit. Lastly do normal exercise. No need to go to a gym or do anything extreme, but just take a walk or a bike to things close by you'd usually use a car for. Take the stairs instead of the elevator.