Hi there, welcome to 3FC!
Feel free to join us in the weekly planning chat....it definitely helps to keep yourself accountable by talking about what's going on during the week.
We have pretty similar stats (same starting weight and goal weight pretty much) but it looks like I am just a tad shorter than you. 121lbs is considered "overweight" for me, and when I saw that number on the scale I decided then and there that I was NOT going to be overweight!! So here I am...
My advice for you, based on your post, is to not give yourself a "time limit" to lose all your weight by. Making a lifestyle change is the only way to truly lose weight in a healthy way, and keep it off for good. Taking things one day at a time, and setting weekly/monthly goals are excellent methods for doing so, but don't just try to lose 15lbs as quickly as possible.
In my experience, I have steadily been losing 1lb per week. I have really cut down on sweets, white carbs, etc. and eat lots of fruit and vegetables, whole grains, lean meat/fish, etc. (if you have any questions just ask!

) I work out 5 days/week (an hour or so of cardio plus weights 3-4x/week) and try to walk outside for 30min. to an hour every day.
It's important to maintain a positive attitude, but I don't think that 2lbs per week is a completely realistic goal for someone our size. Shooting for at least 1lb/week is very reasonable and healthy.
Anyways I hope you stick around at 3FC; it has helped me a lot so far to talk about weight loss issues with other people, and new faces are always welcome!!