friends with a rape victim

so one of my close friends was raped by an older boy in june. i was the first person other than her friends that she told. she’s been having a really hard time dealing with the anxiety and depression as a result and is convinced that the whole thing was her fault. i always tell her that it isn’t and try to say the right things when she’s having an anxiety attack but sometimes i feel like i don’t know what to say. i know that i have to be careful with what i say but sometimes i just don’t know what to say because i will never fully understand what she went through because i’ve never experienced anything nearly as bad as she did. any advice on what to say and what not to say to a rape victim?