How can I motivate myself?

Ra

Hi I'm new to this group. I really want to loose 1 stone. I've had 2 babies in the last 4 years (now 4 and 1) and I want to get back to my pre pregnancy weight. I'm about 1 stone heavier than before I had babies. I would ideally like to loose 1-1.5 stone. I've tried different diets and always loose maybe 5lbs then have a bad day and fall off track and put it back on. I want to feel more confident. I hate my stomach I feel its so flabby now. My bmi is probably 25.5 now and I'm not comfortable with that. I don't have any motivation to go on a diet. How can I loose weight? I eat 3 healthyish meals. My problem is snacking at night.