Starving myself, help?

ok so im 15 years old and I have always throughout my life been very skinny and I loved it but over the past year I've had some personal problems (bad breakup, etc) and I've put on a bit of weight (stomach and thighs) and I hate myself for it and I've tried excersising and eating healthy but it's just not helping so I've just stopped eating from 2 days ago and i'm feeling horrible but I can't stop not eating because I want to be thin and I know you probably think I'm stupid but it's just how I feel so I wanted to know how long do I have to do this for before I loose weight and please don't talk me out of it and say I'm pretty just the way I am cause I'm not gonna listen to you I just want to know how long I have to do this for. and I have no one to talk to either so don't tell me to talk to a counsellor or a doctor even my friends won't understand. thankyou xx