I don’t know what to do anymore….

I am 15 years old, I live in the north west of Manchester, I am in year 11, I am a prefect. I have currently had spinal surgery and ever since then I have been going down a hill. I am getting so insecure, I don’t think I am pretty, I think I am fat (my friends say I am not fat and that I am pretty)  but they are my friends so they have to say that, I don’t think anyone likes me, don’t think I have any friends, I have an ex boyfriend and he didn’t even like me went we went out, I currently like a boy, I think he absolutely hates me, and in my chemistry class this boy said ‘I have everyone’s number’ and then I said ‘ you haven’t got mine, and he replied ‘I only have people I like in my phone’, i did a status, in the heat of the moment and I think I have lost one of my really close friends because of it. The pressure of my exams is intense, I can’t cope, a couple of months ago I wrote a suicide note, and the next day I filled the bathtub with water and stuck my head under, I tried three times in come coming up, but it didn’t work. I told my mum that I have thoughts of overdosing with   Pills, and she wants me to see a doctor, psychologist, but I don’t want that I think if I left this earth I would be doing everyone a massive favour, no one likes me, I am just a waste of oxygen. I can’t cope with anything anymore, I want to die, I don’t want to love anymore.