I gotta agree with BGM here – I’m not seeing the controlling behavior from the LW. Not wanting your partner (or even ex-partner) to hang out with toxic people who are taking advantage of them is a far cry from being controlling.
Any time an ex tells you that you were bad to them in any way, it’s worth considering and introspecting on if it’s true or not. But in my experience (particularly with people who have BPD) just because they say it’s true, doesn’t make it true.
My wife’s sister has BPD and has lobbied several accusations towards my wife and it absolutely destroys her, and they are all wildly untrue. It’s a particular cruelty and it usually involves accusations of behavior that the person is guilty of themselves.