first of all you need to take a look at where and when you over eat. You need to write the following things on a piece of paper and kepp in a safe place so you can look over them daily. I would recomend first thing every morning.
Set a goal
Write down how you feel and look at your current weight e.g. low confidence, lumpy.
Next after this you need to write how you would like to feel and look at you target weight e.g. confident, toned. This will be you motivation to get down to that ideal size and aldso a reminder of how bad you felt.
Why do i over eat ?
Now write down how you are feeling when you over eat. Now think of other things you could do when you feel like that e.g. have a cup of herbal tea, go jogging.