I'm not too familiar with NS.. it seems like you lost weight rapidly. Which is good, and bad. When you lose weight very quickly, it is very hard to maintain.
The nice thing about WW is that it teaches you to lose weight, a little slower at times, but with keeping the healthy side of things in mind. Getting exercise also helps too, which WW is big on with the Activity points. It also sets you up for a good maintenance foundation!
You may start losing weight, but not as quickly as before. Your body does need to adjust to these losses.
Keep up the good work, and you'll get to your goal, one step at a time.
Where are you going on vacation? Just remember to enjoy yourself still.
I always encourage enjoying the weightloss journey. Don't make it hard for yourself, because then it will be harder to maintain once you get there. Eat what you enjoy, but learn to be healthier about it and hold yourself accountable!
keep it up!!!