Really need help here /: ?

Today, at my school, there was an assembly about suicide awareness.. My girlfriend, who has been suicidal, and self mutilating herself for three years.. Is now bound and determined she is going to break up with me, and kill herself, because everyone is saying that I am the reason she is suicidal and cutting... I have only known her for a short while, and been with her for 6 months... Can anyone give me tips, advice or their opinion? I've truly had enough, and am ready to take her way out..