Have you tried changing your exercise at all? The body is an amazing adaptive machine. It learns to be efficient as possible in a relatively short period of time. If you start working out, even if it is walking more, your body adapts to the new exercise. Initially it will not be very economical in energy conservation when adapting to a new workout, but it won't take long for it to do it very efficiently, effectively reducing the number of calories you are burning for the exact same exercise. Also add in the loss of 10 pounds and it is using even less calories because you are hauling less weight all the time.
In the past, I lost a large amount of weight (50+ pounds). When I hit a plateau I tried to shake things up with my exercise. Also, I don't eat the same # calories every day. I generally eat what I burn at least one day a week, while other days I might have a bigger than normal deficit. I'm happy if at the end of the week I average out to my goal deficit.
For me, keeping my body guessing has worked very well. Also, I don't know how much more you want to lose, but it is very different when you get to those last 10-15 pounds. It required a lot more effort on my part. Good luck!
