I want to be 46.8kg(103pounds) again !!!?

First step is that you recognized the issue, which is good. You can stop yourself from further gaining so much weight. You're not overweight, but it's good too take control of your weight now. Make more of an effort to exercise and at healthier. Don't live for weigh-ins, though; weigh yourself maybe once a week to make sure you aren't gaining more weight, but remember that things like clothes sizes and the like count more than the number on a hunk of metal [weight-wise, of course; if you're talking emotionally, your heart and brain and whatnot count WAY more than the number on a hunk of metal :) ]. Remember that trying to lose all 25 pounds quickly is not the way to go; I'd just stick with exercising and heating healthy, and see where that leads you. Good luck!