weight....

I saw some of my pictures from high school, i was so surprised about myself, first of all because i'm not that type of girl, who cares about herself in ways of eating healthy or doing exercises. also i noticed on my clothes. I cant believe that in less then half of a year a gain more than 20 libs. I know if I propose myself to healthy diet i'll lose weight. but I just can't believe it. my mother told me that it is not going to be easy to lose weight and i'm afraid to.