I’m also without words after reading your last messages.
All I can say is think very well the plan you are gonna follow to get out of this relation for good and go to contact zero since you decide to leave.
She has to be convinced that she has nothing to do with you, no matter whatever try she makes to get you back.
She’s even using the technique of triangulation when she tried to make you see that you could lose her for a third person.
Noone deserves being treat like that.

I also was shocked by what you told her about taking her own life away. If you think about it, it’s one of the worst phrase that someone can say to another person. I understand that you said it in the heat of the moment and you didn’t mean it but try to avoid these comments with her. Not only bc it would be a perfect argument for her to feel very hurt and angry, but also for you, yourself. If she would ever commit suicide or a try, you won’t ever forgive yourself.