You did lose too fast the first few weeks and now your body has to stabilize. You could kickstart it again by maybe eating more calories.
Do you workout? If you do you may not be eating enough to lose. I did that for a very long time and I gained about three pounds. I was exercising like a mad woman and not losing so I upped the calories (a lot) kept my low glycemic carbs to no more then 40% and now its' coming off.
It's not as easy losing at 57 as it was when I dropped my first 80 lbs. when I was 44. Now I just want to lose the last 10 lbs. that keeps hanging onto me.
Have a good day!!