Hey R, welcome to the board and I am sorry you are going through this right now but it sounds like you have a lot to work on to improve yourself as a man and a future partner.
Unfortunately, the hardest thing for you right now is to realize there's nothing you can actively do that will change what she's going to do. Nothing.
You need to accept that, process it, surrender to it. That is the hardest part of all of this, the situation, in terms of what she does, cannot be changed by you. It's too late for that now.
If you want to reconcile, you're in a waiting game, and the only course of action that leads to reconciliation, IMO, is emotional distance and not actively trying to fix *anything* between you because that ship has sailed.
You need to focus on you, being the best man you can be, and taking your attention 100% off of her. Do not be her friend, do not be her safety net, do not engage with her at all beyond the minimum you can manage. That's it. Get her out of the house as soon as possible, co-habitation will make things worse.
Does that sound like horrible advice? Is it scary? Are you convinced that certainly it doesn't apply to you?
That's all normal. Everyone feels like their situation is unique, and there must be some answer, some solution they just haven't discovered that is within their control. There isn't. You don't have an option that doesn't suck. You have to pick the least $hitty option of all the $hitty options you have and learn to accept that. The option that [censored] the least is protecting yourself by giving yourself emotional space.
Distance from her emotionally, but be happy, upbeat, successful and positive on your own. Fake it until you make it. That is quite literally all you can do, and that, my friend, is a very bitter pill to swallow.
