Personally, I have this problem when I come home from work. I work at a High school, so I'm home by about 3 everyday. I don't eat until my roomie comes home at about 6-7. So i eat too much then and don't have cals left for dinner and eat anyway. My solution?
I dont know what is feasable for you, but I go out on my balconey and mess with my plants, or I go work on an art project, or I get on here. That's my way of dealing. It doesn't always work, but when it doesn't I do, at least, not eat as much, and I try to eat only enough to take that urge away and then wait to eat until dinner.
I'm assuming you had a snack/dessert after dinner. Because I find that I need a little something around 9ish to keep me from biting my nails until midnight. Sometimes when I really want to eat and it's late, I go to bed early. It's better than consuming extra calories I don't need. I usually wake up bright and early.
The only motivation I can give you is to keep your goal in sight. Think of a cute outfit you want to wear this summer. Try to remember that in July when you're wearing it you won't have missed a few cookies you could have eating in March.
Is there anything you can distract yourself with that will help? reading, writing, tv, etc?
How about exercise - nothing that will energize you and keep you awake, but maybe crunches, or pushups, something like that, to kind of get you in touch with your body physically and remind you in a very physical way the reasons why you want to stick to your plan. Maybe like 20 situps or whatever may help (if it would)?
Life's too short to deprive oneself, though no doubt within reason (this being the key of course). If you're only eating 1300 calories, allow yourself to "binge" on about 300 or 400 calories when you have the urge. On healthy snacks like a bunch of fruit or something. Given your height and weight you could easily afford to eat a few healthy snacks and STILL lose plenty of weight. Being very austere with oneself often has the opposite effect of self-sabotage when we can't as humans keep up with our strict plans. Ease up and have fun while you start your new lifestyle.