Beana
Everything in your post youre talking about how bad you know this relationship is for you and how hurt you are being by it. So listen to that. If it helps, remember it is your own BPD traits that are keeping you tied to this guy.

You know what the healthy choice is.
You owe him nothing. All he has done it hurt you. Do you really want to set yourself up for more hurt?

Hang in there. Hugs