I had a new thought on this subject... I've always thought that the body you have is essentially a true reflection of your lifestyle (barring any medical conditions, crazy drugs or recent radical changes).
You might want to consider the idea that, if you're eating healthy foods in proper proportions and if you're exercising regularly and sufficiently (all of which it seems like you're doing), that you may not need to worry about your actual weight any more. Your lifestyle is healthy and your body will reflect it.
Theoretically, your body should acclimate to exactly the size and composition it needs to be in relation to your specific physiology.
It seems unlikely (if not impossible) for anyone to gain back very much weight if they're running marathons, much less if they are eating healthy foods as well. If your weight were to increase then the same amount of exercise will start to be harder and will burn off more calories. So as long as your exercise and calorie intake are consistent, your whole physiology should self regulate to exactly the composition it needs to be efficient within its own specific biological boundaries (genetics).
You might "want" to be thinner than your body wants to be (in its most efficient state), but it wouldn't necessarily be any healthier for you to be thinner.
It might be time to forget about the scale at this point and trust your body to adjust itself to its needs given your current lifestyle.
Just a thought (I hope someone else hasn't said it already, I haven't had time to review the whole thread).