Breakfast: Mini Bagel with whipped cream cheese
Lunch: Green Salad with olive oil and vinegar dressing
Snack: Non-Fat Latte OR yogurt
Dinner: Grilled Chicken with brown rice
optional snack: 100 Calorie pack
is this a good diet? i'll also be exercising. swimming and yoga 3x a week?
any tips to help me stick with it?

Only if your 5' tall and only weigh 100lbs, if not you'll be starving (your muscles will eat themselves before the fat starts to burn), especially with the workouts. You need LOTS of protein to maintain your lean muscle mass. Every time you lose weight (fat), you also lose muscle mass- which is never a good thing...ever see a "skinny fat person?" You don't want to be one...
This is a MUCH better diet, that will preserve muscle while maximizing fat burning (this is what a trainer and / or nutrionist will tell you to eat). You can eat the meals in what ever order you want, but stick to something close to this:
Meal 1:
1/2 cup oatmeal with a dash of cinnammin* / Splenda
4 egg whites
2 strips of turkey bacon or 2oz of lean ham
(you could replace the oatmeal w/ a slice of organic bread toast)
Meal 2:
1 string cheese and a few almonds
Meal 3:
Turkey or chicken breast sandwich on organic bread
Mustard, lettuce, onion, etc....NO MAYO
Meal 4:
Whey protein shake with water (take right after your workout)
Meal 5:
3oz grilled or baked chicken breast / tenderloins
1/2 c brown rice
Meal 6:
3oz+ Tuna or Salmon with a salad w/ light Italian dressing
You need to eat a small meal (100-300 calories) every 2-3 hours to keep your metabolism burning.
Your diet also need to be centered around protein, and ELIMINATE all sugar, white flour, and fried / fatty foods. Basically, eat as raw and natural as possible.
The only carbs you should eat are:
Organic bread (look for a "breadstore" if you don't want to pay $5+ per small loaf).
Brown rice
Sweet potatoes
Yams
(none of the above spike your blood sugar level like white flour)
Fruits should be limited to low GI kinds. No bananas or other high sugar fruits. Try to eat your fruit earlier in the day.
You also need to drink 1 gallon of water + a day. If you feel thirsty, you're already dehydrated. Your urine should be clear.
Take a multi-vitamin with breakfast.
Eat ONE cheat meal a week (a burger, few slice of pizza, fried chicken, etc.). It will taste better than EVER and give your mind a break.
The above meal plan may sound like a lot of food (I read your other post: 5ƈ" & 135lbs?), but when you eat natural (your body processes this food properly) and often, combined with workouts, your metabolism shoots up and you're body constantly need fuel.
If you follow a meal plan like this and exercise 3x+ a week, you should lose about 5 pounds +/- a week.

I think you need to eat more, try getting more carbs into your diet. Also, try low-fat cream cheese and low-fat dressing

A healthy diet is not just to maintain a good weight it's a way to have a healthy life.....A healthy diet with exercise is a wonder life style. You will look great on the outside and feel great on the inside...just the way you will feel and look will keep you with it trust me on this one as it's rather nice to hear how nice you look all the time.