weight loss

Im a 17 year old girl .. my height is 172 . And my weight when i was 15 years old was 74 and then i got it down to 59 by laxatives and not eating much and going to the gym . I had a great body then . But now all of a sudden i gained soooo much weight . I weighed myself self just now and im 67. I have flabs again and cellulite every where and stretch marks .. i need to lose weight again . Atleat 10 kgs. In maximum two months !!!