one screwed up ting about my life

Okay this is what is on my mind again her my ex-gf brooke.She left me after months of her teling me she loved me alot she just tells me she doesnt love me one day.I didnt do anything that i know of i just loved her.she left me all alone and took OUR friends with her so i was once again alone i dont know what to do?I've tried moving on but its not possible.She was pretty and smart and helped me through everything its her fault i'm not able to cut anymore even though shes gone i still cant i cant do anything else either to drown my sorrows any ideas of what i can do to move on?