Cutting, suicide, hopelessness, depression.. I don't know what to do anymore?

I'm a 17 year old girl. The past 3 months I lost a friend of 9 years and a friend from school due to suicide. I told myself I would never cut, I always hated the idea of it. I've become so angry, upset, frustrated, and worthless that I began doing it. on top of that I've within this year tried throwing up and starving myself in order to lose weight. Ive been made fun of since 7th grade, I am 5'1 and weight 149 pounds. I drank a milkshake today & felt so guilty I threw it up. I know I know, all this behavior is terrible. Step into my shoes for a sec. My mom told me last night 'shes worried'.. "this is how people die" she said to me. I just don't understand, my parents know i'm having problems and they say theyre worried yet they wont do anything about it. they don't take it seriously. Ive thought about suicide as well, something else I told myself Id never do. I don't want to, I just want the pain to go away. I want to be pretty, skinny, smart and well liked. I want a boyfriend too (which Ive never had) When I look in the mirror i'm so disgusted, I know peoples opinions dont matter but when youre told something on a daily basis you believe it. I got angry today at lunch at school & lashed out for a second. Im not normally so angry. Im afraid of therapy, i'm afraid that everyone will think im messed up, im afraid my family & friends & everyone at school will look at me different. I'm afraid of what im capable of if I don't get help. I don't know what to do, my parents dont take me serious. I act without thinking, another reason why im so afraid. I went running yesterday hoping a car would just hit me. I know you're probably thinking i'm insane. everythings just building up inside until one day I'm going to lose it.