I totally believe you have to be in the right head space to lose weight. When your not, you just have to try your best not to gain (too much!). Stress and emotions contribute to food cravings so try to minimise those pressures before trying to lose weight then it works better.
I find combining 1/2 hour walking 5 times a week with 3 x 300-400 calorie meals and 3 x 100 calorie snacks works for me. Anytime you feel hungry think of all the weight you are loosing!!!
Good luck.