Student Exchange Programs

Hi. I’m a 17 year old girl, 160 cm/5′25” inches tall and weigh 75 kgs/165 lbs. I’m currently a foreign exchange student and I’m not having the greatest time. I’m stressed a lot and have read that this will create weight gain. I’ve got 4 months left of my exchange (going home June 13th) and I’m wondering if it’s possible for me to lose 22 lbs during these final months. I’m also wondering if it’s possible to lose 45 lbs by this December, which is 10 months away. My goal weight is 55 kgs/121 lbs by December 2012.