I met this girl freshman year from anoth…

I met this girl freshman year from another friend who moved to chicago from philly. I was good friends with the girl who had just moved to Chicago so I guess i was bound to meet her friend sooner or later. Really long story short me and the friend in philly have been talking for 2 years now, and on average like 5 hours a day and I really feel in love with her. She has hurt me a couple of times but she says she has changed. I told her that this wasn’t healthy to be in love with someone so far away and that we should start to gradually stop talking. She has a boyfriend anyways so I figured she wouldn’t need me like that. She calls me and we start talking and everything is good until I find out she is doing oxycotton. I tell her we really should try not to talk but that im willing to talk whenever she needs it. I feel like this is turning into an abusive relationship; I need her and I feel she needs me but its just not going to work so when i try to end it i kinda feel threatened that she is going to suicide or do something stupid. I dont want to find out she is dead and know that i hadn’t been talking to her. I like can’t live without this girl but I feel i should learn how to but I just dont feel she is letting me, the worst part is her having other boys in her life. I just feel like shit and that im like an emotional drug for her when she needs it even if that might not be the exact truth. What should I do, is this an abusive relationship?