I will try to give some advice that is not really advice in terms of rules but more my own two cents about any diet.
Be nice to yourself
What most diets have in common is that they put up a regimen that makes Jesuits seem lenient with their self-flagellation and use of cilice. Don’t chastise yourself for prior “sins.” Your body is not your enemy. To lose weight slowly is not a sign that anything is broken about you, but that in fact your body works like it was completely sensible for ten thousands of years.
Be self-aware but not paranoid
If you eat a low-calorie diet, you put your body under stress, and your metabolism slows down. You notice when your hands are colder than they usually are, you need an extra sweater, etc.. Your body is not suicidal, it likes to do what is good for self-maintenance. If you notice your metabolism slows down, try exercising (even if you can’t run you probably can still do some lifting or crunches, or push-ups), or just try to eat a little more.
Your body varies. In women, the amount of water in the body is related to the cycle, and if you take care you’ll notice that right before your period, your rings tend to sit tighter, for instance. No need to panic if you don’t lose weight that week.
Find a diet that suits you best. With diet, I mean a way you could perfectly imagine to eat for the rest of your life with some modifications. I know people you wouldn’t want to cross before they had breakfast, and people who just aren’t hungry before noon. Whatever feels fine for you. Don’t eat a certain way because others present it to you as a way of living with almost religious zeal.
You haven’t been paranoid while you were gaining weight most probably, so don’t be paranoid now. Even if you gain one week, all is not lost. You won’t fail a math test in 4th grade and say “Okay, screw this, I’ll never learn it, I’ll quit learning in total” either, or at least it won’t be a sensible thing to do.
The point of it all
I suggest making a list about what motivates you to lose weight in the first place. What I found true (now, and in hindsight regarding some failed diets of mine a good few years back), is that it probably won’t work so well if you defer the responsibility on circumstances and other people, or if you do it to please someone. Don’t do it for others.
So what do you hope you’ll gain when you’re slimmer? What do you think is going to change for the better? No need to show this list to anyone; it is proven that our dreams are less likely to come true if we disclose them to others.
There is a great likelihood that however slim you are, you won’t look like a fitness model. You won’t look like a dancer unless you dance. You’ll still be you, and please, for the love of God or the Spaghetti Monster, start liking yourself as you are now, not only for what you might become.
Whenever you feel like giving yourself a treat (not because you’re hungry, but because you feel you need an extra hug), walk a circle before going to the fridge and think about what makes you want it. (A cake to fix all ills is just as unsuitable for the job as offering a band-aid to Prometheus instead of shooing away the eagle that’s picking at him daily and freeing him of his chains.) Which part of the things that annoy you can be changed, or should be changed? Don’t eat as a method of coping. Been there, done that, and it doesn’t change anything for the better. Please don’t let it become a habit.
You’re more than what the scales say
Please don’t stake your entire happiness on your weight; it’s not worth it. Don’t obsess. Start something parallel to losing weight that gives you satisfaction, something you always wanted to learn, like a language, an instrument, or drawing. It might give you a sense of achievement that isn’t related to your weight.