2lbs per week is too fast. Losing between a half to 1 pound per week is pretty good.
Your diet is pretty strict, mainly on the carbs side. It was good call to take the Centrum vitamins (you might not be getting all the energy/protein you need from your diet, but at least you’re getting your vitamins and minerals right).
It’s a pretty well balanced diet, and the only thing I would say is to try some meat (preferrably poultry) every other day and increase your carb intake. For example, forget the oat bran muffin for lunch, and eat some rice, potatoes (not fries) or bread. Also, try to snack, I mean, try to eat every 3 1/2 hours. You won’t be so hungry and you’ll increase your calorie intake a bit.
Also, if you want, you can really start eating a lot more and just increasing your amount of daily exercise, i.e., running (0%) instead of walking for example, or just walking longer. Try to perform different exercises, not just climbing, so your work different groups of muscles and do not put strain always on the same joint (climbing is not good for knees in the long run).
Also, at 18, you might still be growing. Do not restrict your calorie intake too much.
The average adult woman should eat between 1800 to 2000 calories per day. But it all depends on how much you exercise really. The thing is: exercise more, eat more, exercise less, eat less. However, do exercise; it’s good.