My friend killed herself

i woke up this morning and my boyfriend called and said that a girl a went to elementary school with died. she went missing because she ran away and they found her like 2 months ago and she killed herself yesterday. she overdosed. a year ago i overdosed on a very large amount of pain killers and some how i survived. i feel so... guilty for surviving. why did she have to die? like who the fuck decided that i get to live but the girl that needs help the most dies. this is the second girl in my grade to die. first was a car wreck, now this.... all in a matter of weeks. has anyone else ever felt bad for surviving? is this normal? we are all so young... she was 15. a fucking freshman for gods sake... and now shes gone... and im crying because for once im scared of dying. and if you would have told me this a year ago i would have laughed in your face. but now here i am feeling guilty for surviving... has anyone else ever experienced this?