Good luck OP!
My top tips are drinking a pint of water before each meal or snack, and (this one sounds silly) sometimes I eat meals with chopsticks as it slows me down and gives my stomach time to register that I am actually full.
A lot is psychological I find, when I haven't drank much water I am super hungry and I feel miserable about the small size of a meal or snack before I even start to eat it, because I know it'll be over too quickly. But when I've filled up a little on water I find I enjoy the smaller meal or snack as much as if it's a bigger one, as there is less space in my stomach for it to fill.
Healthy eating gets a bad rap but it's a pleasure to eat a diet full of lovely tasty healthy nourishing food, I just had a really basic avocado salad for lunch which was around 380 calories (almost all in the avocado) and absolutely delicious! I'm a chip fiend normally but it was as tasty as a chippy, just in a different way, and without the guilt and grease regret after.
I also recommend not cutting anything out of your diet, you can eat anything you like as long as it's within your calorie goal. So you can have that 400 calorie pastry if you really want it as long as you're willing to cut your dinner later down to a hundred calories. Thinking of it in that way really makes me think twice about whether it's actually worth it or not.
I save loads of money too not eating out.
Enjoy it, enjoy treating your body well and promoting good health :) and well done for having the determination to do something about the problem before it gets worse and you have even more to lose. Whenever I feel down I remind myself I'm only losing a stone and a half, and there are amazing people out there who've managed to lose ten, twenty stone, so I'm sure I can do this.
It's a cliche and I know it was co opted by the awful pro ana movement, but I strongly believe nothing tastes as good as thin feels. The pleasure of enjoying my body and liking how I look and being able to wear lovely clothes without limiting myself far outweighs the momentary pleasure of the extra food I don't need.
Preparation is so key too. Do a meal plan for the next two weeks and a food shop specifically for that food, get a meal planner board and stick it on the fridge so every day you know what you are going to be eating.
And finally, every night when you finish your MyFitnessPal diary, input your food for the next day. I find it much easier to stick to when I wake up knowing what I'll be eating instead of having to make those choices during the day while I'm potentially hungry or emotional in some way.