My first thought on reading your post and your profile info was that 115 is an awfully low weight for you to be trying to maintain. As WaterRat says, I do hang out in the 115 range (or at least I try to) but I'm shorter than you (there's some question as to how tall I actually am--according to my annual check-ups for the past three years, I'm somewhere between 5 ft 2 and 1/2" and 5 ft 3 and 3/4"--I always go with 5' 4" because I can weigh the most at that height according to my BMI
). I've been able to maintain at this weight at up to 1900 calories per day. The fact that you have to eat less than 1500 calories per day to maintain your weight makes me wonder if maybe you are being too hard on yourself.
Are you strength training? If so, are you sure those 2 lbs aren't muscle? 'Cause if they're muscle, you really don't want to lose them. Do your clothes still fit the same or are they tighter? How about your measurements, have they changed?
When was the last time you had your body fat measured? Maybe, instead of focusing on the 2 lbs, it would be beneficial for you to focus on your body fat percentage and, if you aren't already, add some strength training to your workout to work on toning and building lean muscle. Muscle would also increase your metabolism, which would help you reduce your body fat % (and possibly lose weight).
I know how scary it is to decide that a goal is too ambitious. I originally had set my sights on 110 and just couldn't get there. It took me a long time--almost a year--to admit that 110 just wasn't realistic for me. I decided this year to set my red line at 118. It was a difficult decision; I thought about it for weeks. It felt like I might be starting the slippery slope to gaining all the weight back. But I really think it's turned out to be the right decision for me.
Paperclippy, I love Harry Potter and "Constant Vigilance" is my motto! It's even in my profile!