weight

so I'm overweight. I am 5'1" and extremely overweight. I have gotten to the point where I have began to obsess over it. my mum keeps trying to get me to lose weight. she says I Need to try to be losing 2-3 lbs a week and is putting me on a calorie diet after my birthday... I'm turning 16 this July... all my friends say I look fine and that I don't need to lose weight. so I guess my question is how can you not obsess over your weight. (btw I weigh over 200)...