Need help with girlfriend and her addiction to H

[Wallst]

So I really need some words from someone and not just , "leave".
I took the girl I'm seeing, to the hospital last night. She had a lot of pain and other issues causing her to not have her period for 5 months now. I stayed the whole night through. Her cell phone died and around 2am I get texts from her X. Him and I exchanged words before and this time he was demanding to talk to her and I wasn't trying to be rude whatsoever. I told her he was texting me and she got mad that he kept saying these things to me. Anyway, his last text was that he would be seeing her anyway. So we leave hospital at 8 am and I get dropped off at home and she leaves to supposedly go home. I text and nothing for hours. Then I just got fed up and text saying that I know she prob went to his house (he supplied her heroin) and that it sux that I was there all night and this is what I get? She responded telling me that we cannot be romantic any longer and that she is gonna focus on just her and that she is tired of the same arguements with me . So she said she disappointed but letting go and she's done with me. Where did this mood swing come from? I just can't believe that she would use right after we just went to the hospital. She said she going to heal now and she is letting go. Is she high? I really don't understand where I went wrong. She says that my texts to her X were rude and that the bickering between him and I was wrong and that I at least could have waited till she was discharged. I just see if I'm the guy she called for the past 2 days, to take her to hospital, how she just discards me like this. It just hurts and she shows no emotion. I know she has told me like a month ago almost the same thing and then 2 weeks later she is texting me telling me she's in pain etc.... So do any of you think that she went and got her fix and this is how she's acting or did I screw something up somewhere where she just texts me saying " she's fed up and that she is stressed and that she is now going to heal herself and do her" why would she hold on to the bad X that has abused her and destroyed so much around her, and discard me, the guy she said was her positive light, the guy she says she cares for. Help people, I'm lost. Why did I ever fall for her?