How do i stay motivated with going on a diet?

I know I'm not fat, but I feel very unhealthy. I've been overeating for the past month. I've gained around 9 lbs, and I just feel terrible about it. I'm 114 and 52. I know it's not bad, but I used to be 105 lbs.

I'm always good about the way I eat,...

until the end of the day. I guess it's because I feel healthy by then, and want to quit my diet. But then after dinner, I feel bad again.

How many calories should I eat a day to get to 105 lbs by Christmas?
How do I boost my metabolism?
How do I stay motivated?

PLEASE HELP! I'M DESPERATE!

sigh keep this in mind. no matter whatever site u search u will always get these answers i'm about to give u. ur the nth person to have asked this.

BOOSTING METABOLISM
eat 6 small meals a day- u wont feel hungry so often. and u increase ur metabolism as ur body constantly is digesting food and that uses energy.

EXERCISE-the best way to lose fat and keep it off. at least 2 hours every week.

DONT CRASH DIET- dont EVER EVER EVER starve urself. why? ur body ramps up ghelrin hormone that kicks ur body into a survival mode. storing fat, eating away muscle, and slowing metabolism so u can survive on less food.

lay off the white stuff. like white rice, white bread, flour. go for wholemeal bread, brown rice, wholegrain, etc. white stuff has little dietary fiber. which means the carbs go quickly into ur body, and get stored as fat. eating stuff with dietary fiber releases the energy slowly.

hope this helps.

write down what you can and can't eat, prepare you meals ahead of time. Possible even take a day off from your diet