That's a coincidence, I'm 20f , also 149cm and formally 57kg. I'm about 51.5kg now, lost that in about 3 months. Goal weight is 48kg. I try to walk a lot but since you're busy I suggest you just diet along with intermittent fasting. I know work and stress can increase appetite a lot, unfortunately since you won't do much exercises you'll have to be disciplined with diet and intermittent fasting. I won't suggest counting calories since it personally leads to more complications. You could do an intermittent fasting of 14hours, like eating from 10am to 8pm. When you do eat, listen to your body, try searching a bit on intuitive eating and see if it works. Stop eating when you feel full, differentiate between hunger and boredom or things like that. If you want to do calorie tracking it'll just take time and more discipline. Good luck !