Throwaway for obvious reasons. I'm currently in a 1.5 year old relationship with a caring, forgiving SO I probably don't deserve. If she presented her side of the story on Reddit most of you would probably advise her to dump me straightaway, but for some reason she didn't. We've had our ups and downs but for the most part it's been great for both of us. We've considered ourselves polyamorous but I've fucked up big this time by lack of communication. 

There was this girl we've both had sexual history with, but we decided to stop seeing her (in a romantic way) due to her being unstable, manipulative and could have been a potential threat to our relationship. After that, we've seen her a couple of times together, usually from my initiative. She always claimed that we mistreated her, using her as a toy to satisfy our needs but I've had feelings for her just as strong, I've just never seen her a relationship material as she wasn't ready to commit and she was too immature to be any more as a friend, so i couldn't really act on my feelings. Fast forward she cuts off any contact with us as supposedly my girlfriend posts some stuff online about how her being in our lives affected our relationship negatively. Out of the blue she blocked me and stopped talking to me for months but then we stumbled upon each other randomly online on her fake account and that's when she told me her reason to cut off any contact, which might have as well been a lie, as my gf denied all of that.

We kept on texting for two months which my gf knew about, but she warned me how manipulative this person was and how I couldn't control my feelings towards her. I've always felt a sense of guilt towards how we treated her. I was depressed to the point of being suicidal on and off during that time. When we finally decided to meet irl, we agreed not to escalate it anywere past the point of friendship. At the time she was right after the breakup with a person I didn't know and heartbroken as she couldn't be in a relationship with her flatmate she loved, as that person commited to another mono relationship (all 4 of them who lived together used to be in a poly relationship). She relapsed to her opioid addiction two days before we met at her place and i'm treating a poly addiction myself so I couldn't resist getting high with her. In this state all of our feelings were amplified greatly and we felt a stronger connection than ever. I didn't like how my gf was jealous of me and at the same time my ex (lets call her that from now on) kept talking me into how her behaviour was harmful to me. And that's when I cheated on her first, not only physically but also emotionally. Hate me all you want, I can't possibly feel anymore guilt for what I've done anyway and I'm incredibly grateful to my gf for giving me a second chance here. At that time my ex also asked my if I want to help her overdose or commit suicide together at the same time but I wasnt at such a low point in my life to do any harm for myself and I believed she would recover from her depressive state as well.

I felt like my gf didn't want to know everything that happened during that time, pretended not to see instead so I didn't disclose the whole truth. Even so, I progressively tried to explained how I still felt something special to my ex. I wanted to meet her again as the old feeling towards her reappeared stronger than ever. My gf agreed to her coming to our place while she was away at her mother's place as she didn't want to restrict me seeing my friends (I've been pretty antisocial due to depression and lockdown for a while). During that time we've been texting and confessing our emotions until two weeks forward she came, high, still on a bender. In the meantime she lost her job and was about to go to the psych ward just after her visit here. I managed to get clean again during that time and she agreed not to take any drugs to my place. When she came we've had consensual sex but I couldn't resist but ask her to share the morphine she had with me (she broke the promise and took it here). Then she took it all out on me, calling me a monster with no feelings for being a trigger for her plus uncovering past things we've worked through like me teaching her how to inject a year ago which quickly spiraled her into addiction (i never recommended she try it, I even advised against it but yeah giving her the instructions was the mistake). It was as if she just waited for me to say it as she took out her paraphernalia straightaway and shot so much she went unconscious.

When she came around she would turn 180° from calling me the love of her life and a heartless sociopath. I got her methadone, a drug hard to overdose on which would reduce her cravings for opioids to shoot and we spent what I thought was a nice, platonic evening, taking strolls and watching tv series but out of nowhere she kept on saying how i'm faking my feelings towards her and i was simply ignoring her the whole time. I went to bed early as i had classes the next day, at 6am she wakes me up in paranoia not knowing who she was and where she were, apparently she overdosed on something amnesic. She kept on asking the same questions and begging me not to leave her and threatening to cut herself or kill herself if i don't love her. Even though i said i would at one point she took out a razor and absolutely massacred her right arm even though i tried to stop her. I can't get that image out of my head. I was torn if i should call for help, i tried contacting my gf or close friends but everyone was asleep and my ex would beg me not to call for 911 as they would treat her even worse plus I was worried she would frame me into drugging her. After that she would look at her arm countless times and wonder how that happened. I realised i need to send her home asap but she would cling to me as strong as she could and i couldn't just send her out in a psychotic state. 

I spent all day with her trying to calm her down and get her to buy an evening ticket home but she refused to leave. I explained to her that she mistreated me and i can't love her after what she did but she kept on threatening me further she would harm or kill herself while telling me i was the only reason for her being alive, othertimes saying she would destroy my own life. I tried pushing her away but she would cling to me as strong as she could promising she would let me go just after one more hug or kiss. I survived like that on partially being asleep till 10pm when my gf came and i drove my ex to the train station where i promised to send her off. She broke down and lied down on the street in front of the train station until some women picked her up, I gave her stuff back and they left together, that's when i last saw her, Sunday evening.

I was traumatised enough until wednesday morning when i heard from mutual friends that she overdosed and nobody could save her. Apparently she told her flatmates that i assaulted her sexually during that weekend which is obviously untrue. The police is looking for any information on me but mutual friends refused to give it as obviously they realise it must have been a lie. My gf asked me questions about what really happened between two of us. She's very upset and rightfully, but she gave me a chance knowing that even though i fucked up i was manipulated to some degree, tomorrow we're seeing a couple counselling therapist. I'm worried about my relationship. I'm feeling guilty for her death, maybe it wasnt my fault but I could have called for medical help. My ex's closed ones hate me and I won't be able to see her for the last time at her funeral even though i'm one of the people who mourn her the most, believe it or not. I feel ashamed for mistreating my gf. I'm feeling very anxious and distrustful towards other people. I don't know if there will be any charges placed against me, but even if there arent, I will still be traumatised for a long time. Please help me. 

Sorry for the long post, i still missed out some parts, feel free to ask if you want.