Hurting someone I love

Hi, I have been wondering about this topic for a while now. This is a bit of an 18+ discussion. I was in a relationship a couple years ago and it started in 2018. I was not mentally well so we broke up not too long ago she talked to me about how she had a crush on someone (we stayed friends). This got me really upset and I broke a promise we made before. I promised to never do anything with either of out other two friends (we are a group of 4). Well after she told me about that crush I went and flirted with one of our other friends out of hurt and they flirted with me back. I ended up sending a nude photo but deleted it right after out of guilt. So they never saw it. I hid this from her and so did my other friend. After a few months we got back together and went through some ups and downs. I was easily jealous of how much her and our friend got along I will call her L and my now crush/friend A. They understood each other on a level I felt I didn’t. We had good convos and chemistry but deep down I felt L was better than me. So we ended up breaking things off again a year or two later. (We both used to crush on L I did out of needing love while A did because she liked her but then noticed me and A loved each other more than we did L in a romantic sense.) After this break up things weren’t doing good and we would get into fights because of my jealousy which I feel was because of past friendships and projecting my mistake on to her… (we stayed friends because of being in the same group and still having feelings for each other). Out of pain and anger I once again went to another person and that person was L. I told her about my thing that happened with the other friend and started kind of flirting with her out of spite and out of desperation of attention. It didn’t go far because I felt disgusting so I stopped and hid it from A once again and L didn’t say anything either. Some time after that A went on L’s *** to help her out with a boy problem of L’s but after went to her chats with me and her. She read about what I said that happened with our other friend and about my kind of flirting with L. She confronted me and I lied to her even tho I wanted to say the truth out of fear. She then told me how she saw everything and we got into a fight and didn’t get back together again. The last time we were together was early 2020. We stayed friends but it has been painful for her. She says she can no longer be close to me because of what I did back in 2018 and 2020. We flirted still and still do up to this point because we still love each other and can’t let go… She recently told me she can’t be close to me or the other friend but after a talk with L she can be close with her because she said she wouldn’t have done what the other friend did. (Even thought she comforted me and said we weren’t together so it was okay and A saw that) She also said to A that she would of left me if it was her. I pleaded for her back once again out of fear of losing her. I made a mistake out of anger and hurt and can’t take it back. She has told me time and time again she can never forgive me for what I did. I don’t want to lose her…it would be so painful…from close calls With her I know…I know I should probably stop talking to her and give her closure but I don’t want to lose her because of something I did because I was petty. Especially if it wasn’t something I didn’t regret right after. I should of told her before the first time as well and maybe we could of worked things out but I can’t change anything. She recently had a sleepover with L without including me because L invited her and she didn’t feel she had the right to say anything? I also always try and budge into their plans out of jealousy because I know L is better than me and could steal her away from me a time she wanted to and be the friend to A I could never be. They are currently at her house now finishing plans and I know if I said I was jealous I would lose her straight up. What should I do? I don’t want to leave. I also promised to never be friends or date anyone else again after this. So if I break up the group and leave and am alone with just my sister and brother who have their own lives. I will have all the letters and chats we had together and can only see it as a memory…I have had people I liked before and I saw others as my friends but I could get rid of them so so easily when I noticed myself worth but that’s because they hurt me…she never has hurt me other than tell me at times she hates me and tells me we can’t be close which is warranted after what I did. We weren’t together but I broke a promise I told her I would never do over for years. I can’t help but think I should leave her to be happy and be alone like I promised her and myself. Or should I try and be the best friend I can be to her without being able to be as close to her as L is and suffer that pain but being able to have more happy moments being by her side and talking to her. Should I help her not hurt anymore by leaving or should I make the pain less by not trying to be close like she asks. She wants the group to be together after all of this so should I stay to keep the group together. I want to stay so bad cause I just want to feel like I’m someone to her but I will never be forgiven or be her favorite person. Even though she says she won’t pick favorites it’s obvious it’s L. I love her so much and haven’t loved someone so much in my life. I ruined things and idk what to do. No matter how many times I apologize and tell her I truly do love her and have truly changed when I get jealous and have my mood swings it makes her feel other wise… I regret what I did so much I think about it every single night and regret it every single night. If I just went to A instead of our other friends both times things wouldn’t be like this. If I wasn’t petty out of pain of her not wanting to be with me at times while broken up things wouldn’t be the way they were. I can’t change that tho…all I can change is who I am today. The fact that I did it tho weighs on A’s mind and even if I have changed even if I wouldn’t never do it now I did it then….