BPD herion relationship help

[Scatterbrained]

Hi this is my first post and first time speaking about this. Ive been having a hard time lately. And I really need an ear or advice. I've been with my girlfriend for about one year this past December she went to California for a drug rehab. They also we confirm the diagnosis of BPD while she was there also during this time I signed on to a lease for the apartment I currently live in. I'm thinking I ignored warning signs and went for it anyways I could see signs of drug use I guess I didn't think it was that bad. Well it was she had been shooting heroin I Can Only Imagine it was to get out of her own mind dealing with BPD. She came back from California in January and everything was good for a while until we started talking about getting another apartment or house. It's about an hour and a half from where I work so I was a bit skeptical about moving there for another full year in that time she told me that we had the time to think about it. Later I found out she had been sending other guys pictures of herself because she thought we were going to be over with we had some more arguments some got slightly physical. She said she stopped talking to those guys and blocked them on different social media but just recently I found out that she had been emailing one and slept with him and she says to forget me. We went to to counseling sessions before I found out about her sleeping with the other guy it only happened twice but I was shattered and still am the second time it happened she was getting heroin off of him and it was just fooling around in the car as she was nodding out. I know this is a bad situation to be in and I doubt it's lasting much longer but the lease is up in the apartment we are in and she has been getting Naltrexone shots. The plan was to move into her parents basement where everyone could keep an eye on her. Her parents are more accepting of her mess up with drugs since she came to them and told them. But yesterday on Mother's Day her and I were talking and she wanted to break things off with me I didn't feel like I got a word in edgewise for how I felt she said I made her feel bad. It hurt to hear that because I never wanted anything to end this way. She was going to sleep down on the couch and took this battery powered night light Moon down with her and I was going to turn on the gas fireplace so she didn't get too cold. Something went off in me and I took the Moon light that I bought her for Mother's Day threw it against the wall and broke it into little tiny pieces said this is what she did to my heart when I found out the pictures never stopped and then smashed it some more and said that's what happened when I found out she slept with that guy. She started crying I would have too if I was dealing with me. And then I found a cup of water next to me and I threw it in her face. I let my hurt and emotions get the better of me and I rip someone apart who is important to me and no matter what she did she didn't deserve that. That seems to be the shortest version I can post so sorry if I'm rambling. But my questions are as follows. I've always had a temper in that punch holes in walls or throwing things is it common that BPD can amplify other people to that point? Also is it normal that BPD would go and cheat when faced with perceived rejection? I know she did wrong by me but that is no excuse is my behavior if anyone has any insight or has been on either side of where I am right now it would be greatly appreciated thank you for reading my upsetting ramblings. Also the apartment needs to be cleaned up and I'm agreeing to help clean it since I did live there I don't want to put that all on her she said she would stay at her parents this week but I did not want to disrupt her 5 year old Sons routine. How do I stay there for the next few weeks to clean and maintain each other's personal space? Somehow even after all of this I don't think she's a bad person I don't think I'm a bad person just sad and it hurts

[PLEASE - NO RUN MESSAGES]

PLEASE - NO RUN MESSAGES This is a high level discussion board for solving ongoing, day-to-day relationship conflicts. Members may appear frustrated but they are here for constructive solutions to problems. This is not a place for relationship "stay" or "leave" discussions. Please read the specific guidelines for this group.

[Scatterbrained]

Something that I would like to add to the above. I was diagnosed with ADHD about 2 years ago I'm unsure as to why no one in my family saw it took action. I found out at 30 years old. This supposedly explains my freak out slash Tantrums. I'm not making an excuse for my actions but trying to modify my behavior anyone else has dealt with this either through themself or through someone close what helped? How is someone able to calm self before getting so upset and explosive I often find myself getting more upset when I figured out I'm already too upset. So I can understand how my ADHD and my partner's BPD can be very bad when mixed together again any help or advice would mean the world to me