Hello my friend, I've just read the whole lot - tough territory for you and for many on the forum too. So, some suggestions from a female who has been the leaver and the left.
Firstly if you're the one doing the leaving, do the leaving. By this I mean once you've said it is over accept you are no longer responsible for helping her be ok about being left. It is incredibly hard to process someone saying they don't want to be with you and then having them check how you are every few days. It maintains a link which actually no longer exists.
My husband managed to be friends with his former partner for several years after they split. He made her feel good about herself when she had behaved rather badly, I think it helped her but it had horrible consequences for him. Your ex partner may work very hard to ensure you feel ok about leaving when really she should spend time on herself. It might make you feel better, but at the moment that's not her job (I don't know if it was when you were together or not) and even though you may not mean to make it her job, it just does.
For you, to make a clean break might mean you feel a bit worse about yourself as you're not there to help make it right, but you can't make it right, horrible though that is, especially if you have been good at making things right in the relationship. It's a terrible thing but there are no heroes in a separation.
For you to come out ok means leaving, for her to come out ok means you leaving too, not half leaving. There's a complicated psychological explanation that involves the receipt and sending of mixed signals in this situation, because I can well imagine that it is horrible for you too. You don't want to be the bad guy I imagine, and the leaver is often cast in that role. Well, it's not true. The leaver isn't bad, they are just the leaver.
The last time I was broken up with I desperately wanted him to come back and be back. But when he did, just to check up on me, he left all over again each time. That was bad. In the end I realised that it met some need of his for me to say it was ok for him to leave. He needed permission at some level. I recognised this but was in no position to give it. If this is part of what's going on, I very much regret you have to give yourself permission.
Last time I was a breaker up I read up quite a lot about it. The best visual I have is a piece of bluetac - stay with me, I'll get to the point quickly. Imagine a piece of blue tac. You know quite warm and sticky. To break it in two you can go two ways, one you stretch and stretch slowly until it gets thinner and thinner and gradually breaks leaving at sticky mess and trail and hanging bits. The other way you snap it in two. It's a bit brutal and sharp and the bits don't always come away cleanly but it's done. You could go either way, snap it, which I know is tough for both parties, or go for sticky and protracted, which is also tough for both parties.
So, I guess what I'm asking is, do you need permission? Do you feel like you have to be the one to sort it? (You may have been the sorter in the relationship) are you the one who makes things ok? And if you answer yes, to any of these, do you have a sense of what might help you feel like you should be responsible only for the things that are to do with you and not for how your ex partner feels or recovers? Because I really believe you are not responsible for her ongoingly, she has to be free too.
If any of this comes across abruptly, that's absolutely not my intention. I have a feeling that there is a lot of chivalry amongst bushcraft men who in general hate the thought of upsetting the women in their lives and who would do anything rather than that. So I really feel for you. And even if you're not the chivalrous type, more the caring empathic bloke, I know this is really horrible for you, but you can't heal someone else's hurt especially if you caused it, that can just be a bit of self ego stroking masquerading as care. sometimes a short burst of hurt prevents a whole world of hurt later.
I'm writing all this because it's tough to know that leaving really means leaving. And that's kinder in the long term.