I think that the amount of weight you lost is too much in that time frame. Congratulations, although, for making such an effort!
I think it's suggested to lose about a pound a week, but no more than that. When I lost my weight, I found that when I leveled off, that I was still extremely hungry. That's the body trying to get you to eat more to gain the weight back. You'll notice that for months, I believe. So, you've only begun....
In my opinion, since you've already lost so much weight, I'd increase the calories so that the weight loss is not as much. That's great that you are exercising. That's key. Have you switched to natural (non-processed) foods? There's so many different opinions on what is the ideal diet, but basically I think one should first stop eating the junk foods.
With a healthy diet and exercise, your long term efforts will pay off. If you go back to the "old ways", then you'll most likely just gain it back. It's a tough challenge to do it, but it sounds like you're doing great and that you'll succeed.
Starvation Mode? 
Linear Mode
