Pinterest has some great pictures and info under female fitness motivation. They are very um inspirational
Anyway for what its worth I do the same thing. Spend all week watching my calories. feel a bit deprived so treat myself on a Friday. Takeaway meal and suddenly my 3 or 4 lb weight loss week turns into a 2 or 3 lb weight gain. Thankfully as it is mostly water gain through salt etc it goes over the next 2 or 3 days and I usually balance out. It destroys my motivation.
I think the key is to find an eating plan where you do not feel deprived. I've been trying to find healthier versions of all my favourite meals. That way I can include them at various points in the week without doing too much damage to my diet. Even if it means going 100 or 200 cals over odd days. Guess that is the ultimate goal to find healthy food that is enjoyable. That way is not a willpower choice just something you would normally eat.
One good tip I was given is to make soups from favourite meals that way you can take half your normal portion size. Chunk it up, add few hundred mils of stock. Job done. Chicken tikka masala with rice soup, Roast lamb with potatoes and greens etc
Good luck with it all.