Me and my gf got into a fight and i think she ran away from home.. what do i do?

We got in a fight cause I went to my friends house and I did tell her I was going there and she thought I was lying and she called me last night and said she was gonna kill herself and that i'm the reason for that.. Because of her thinking I lied to her when I never did.. I was so upset last night I went home and put my phone down but I didn't wanna talk to her cause I was just upset and she called my phone 99 times and I didn't answer.. And now her phone is off and her family is on her Facebook trying to figure out where she went.. What do I do? I'm just breaking down it's all my fault.. :( I just want her to be okay but idk what to do.. Any advise? Thanks..