Thank you for posting your query. I can understand your concern.
Let me first give you a good news . At your height , your ideal weight should be around 52-56 Kg. So it's just a matter of 5 Kg. Let me help you with a plan.
Try to maintain a balanced diet with cereals ,
proteins ,vegetables . Even a little oil and fat is also required. Try to eat around 4-5 fruits a day. Keep away from fried food , soft drinks . Have small meals at regular intervals.Drink loads of water. That's all about the diet.
If you don't have time or provision for walking , you can try walking inside your house , say start for about 10 minutes at two different times in a day.
Gradually increase it to 20X2 and so on....... Where there is a will , there is a way.
Have patience. You will definitely succeed.
Feel free to post any other question.