It certainly sounds worth a try.
But it really is hard to pinpoint the EXACT reason of your slow down.
You did mention that your exercise was diminished and if I do recall correctly (I could be wrong and if so I apologize), you had a couple of celebratory off plan meals during that time. Also, like someone above mentioned, you ARE smaller, you've lost QUITE a bit (a real LOT) and it may have slowed regardless.
Even though you may never be able to know the precise reason for the slow down, I have no doubt that you will CONTINUE to lose each and every excess pound on you. You are one determined and committed lady. Tis' been a pleasure to witness your incredible journey thus far and I thank you so much for sharing it with us
.