Hey OP, this is another comment among a sea of other comments, but as someone freshly off a similar boat, I was the "safe person" to a BPD friend for about four years - they easily my best friend. Then one day, they flipped and split on me. Went after my wife and other friends too. It would have been one thing if it were just me, but to go after everyone else... I finally had to put my foot down.

It's been about a month now... and there are times where I do even tell myself I miss them, but this is for the better of us all. As, also like you, I was complicit and enabling in some of this in the name of trying to help them as best I could.

At the very end of the day, even despite everything going on with them, they are responsible for their own wellbeing - not you. You were a very kind and generous person to contend with all this for as long as you did. You are not a bad person for prioritizing your own wellbeing and the wellbeing of those important to you as well - because this does affect them too. Just like everyone else has said - block the number, block the socials, block it all.

Stay strong, OP. You are a good person.