I don't know what to do

I'm a 16 year old girl. Last year I lost a lot of weight leaving me underweight, I was taken to the doctors and nothing happened, because it was quick "weight loss", my gp wanted to work out my Bmi so she asked me my weight and I lied. I told her I was 6lbs heavier than I was. So nothing happened, so I continued restricting and obsessively exercising for another 2 months, then I started to eat more and I lost more weight. I decided that I should try and gain weight or recover to reassure my friends, and I put on so much weigh it was disgusting. This summer I bought my first pack of laxatives, and I guess it was one of the best things I've done, I hate the feeling of being full but most of all I hate the fat that covers my body. So September 2015 I decided I was going to do something about it. It's now Novemebr and I'm going crazy my mom took the batteries out of the scales and I'm freaking out I've weighed myself everyday for the past 3 months, in the last 4 weeks I had lost 10lbs and it's really stressing me out, I can't stand myself. Everyone around me, my family, believe it's self inflicted and I'm making problems for myself but I don't know what to do, I'm the problem and breaks me inside because I didn't choose this problem. I haven't eaten lunch at school properly for over two weeks because I just throw it out, I hate the feeling of being full or my clothes clinging to me. I don't know what to do, I feel like I'm falling into an even worse place then last year. My friend says I'm sick and I need help but I'm scared, I feel like I'm not thin enough or ill enough to have an eating disorder, but I'm governed by endless rules in my head and consequences, and I don't want to lose control.

I don't know what's wrong with me.