Congrats on your weightloss so far
... the last 10 are definitely the most difficult to lose ... Good for you also for starting an exercise program it's very important to maintain your weightloss in the long run...
1000 calories/day is not a lot and you're probably not getting all your vitamins and minerals with such a low calorie intake... I'd stick closer to 1300 to 1400 / day it's just healthier...
Doing High Intensity Interval Training (HIIT) burns up a lot of calories, Google it for examples of workouts...
Hope this helps and
to Featherweights...