After 7 straight months of exercising, is it possible to keep my weight off permanently if i maintain only a healthy diet with no exercise? i haven't exercised in 2 weeks, however my weight continues to drop. could i have developed a fast metabolism?

Weight loss/management is 80% diet change and 20% exercise. Over the long term exercise allows you to eat more with a stable weight and maintain a stronger frame/muscle mass. Your metabolism has more to do with activity level than diet. A sedentary lifestyle will lead to a slower metabolism over time.

Exercise has more benefits that just weight control. Regular exercise is good for both physical and mental health. Keep up the exercise. Any exercise you can manage will do. Wish you good health!