So much of what you went through sounds so familiar here:
the emotionally addictive relationship; the emotional intensity; the roller coaster of good times being really good and bad times being really bad; her suicidality; her seeming ability to jump right into a new relationship; the impulsivity; the unhealthy ways of relating to kids/stepkids; the multiple "recycles"; and, over so much of this, your profound confusion -- if you don't want to be with her, why is her breaking up with you so much worse than you breaking up with her?
Many, many members have gone through similar situations. It's not easy. These aren't "normal" breakups.
One idea that gets discussed here is the idea that while we have no control over what others say, think, believe, or do, we DO have 100% control over ourselves. I think you're seeing some of that when you say:
I don’t want to get back together with her anymore but I can’t stop thinking about her all the time, I just want it to stop so I can move on with my life now. It’s affecting my self esteem giving so much power to her in this friendship, since she’s the dumper she thinks I’m at her beck and call. Me deciding when we break contact gives me some control back over the situation for my own mental health?
I also think you're getting part of it when you mention:
We are going to bury it together tomorrow then I’m telling her we should give each other space for a while now, the cycle has come to an end.
An interesting idea about boundaries is that true boundaries aren't ultimatums, and also don't require anyone else's agreement, participation, or cooperation.
I don't think I see you laying out an ultimatum, which is good. It'd look like "Ex: Don't you dare contact me again. I require you to not reach out!" See how that isn't really under your control?
The idea of telling her "we should give each other space" is getting closer to true boundaries, yet it still contains some belief that you can ask/request/suggest to her what she should do. That isn't something we can control.
The nice thing, though is that you can control giving/having space on your end, and it won't require her to agree to or cooperate with anything! And, true boundaries don't need to be announced. True boundaries are about what we choose to allow into our lives, and we can just "do" them whenever we choose.
So, it's good that you realize you need space. One way of having that need be a true boundary could be telling yourself: "My boundary is I need space from my ex. What I have control over to make that happen is: I will block her number and unfollow her on social media. When others try to tell me about her, I will tell them No thank you. If she tries to get in my space some other way, I can choose to not engage".
Notice how none of that requires her to agree, or tells her what she should do?
I think the hardest part about true boundaries is that they make us face what we really want. I just hear the struggle you are going through, so it'd make sense that having true boundaries about not letting her into your life, could be so difficult and painful.
The other "nice" thing about boundaries is that they don't have to be "all or nothing". For example, it isn't that either you guys are together, or you have to cut all contact. You can decide what you can handle right now, and personally set a boundary about that. I.e., you might decide that you need to unfollow her on social media, but you can handle keeping her number unblocked, and you might tell yourself "My choice is that I do not reply instantly to messages from her. I will choose to wait at least X hours before deciding to reply or not". That could be a boundary you choose.
Anyname111, there's so much to discuss with you about your situation and challenges. While I have to wrap up for now, feel free to check out other members' threads, and post when you feel ready. Glad you're here;
kells76