Can I tell you 2 quick stories?
I work with refugees, and some are lucky enough to get sponsor groups. Unless they're trained really well, most sponsor groups tend to do everything for the refugees, instead of empowering the refugees with tools they need to succeed. I mean, how could you not, considering all they've endured to find a new life? BPD may have played a role, but please know that it's really normal for native-born people to do exactly what you're doing. It's not too late to set boundaries. In fact, empowering them to live independently is the most loving thing you can do for them.
At 28 I found myself a single mom with three kids and nowhere to live. My church was kind enough to lend me a house they owned. When my kids and I moved in, it was with a very explicit deadline - the expectation was that I find a job and move out in 6 months. I was scared and alone so back then, their deadline felt a little extreme. My entire life had been upended. Now I look back and I realize that the boundary they set is a large part of the reason I'm independent and successful today. Empowering me to live independently was the most loving thing they could do for me.
I feel like I do not know how to be kind to people who need help but still set boundaries that keep me safe from being hurt and exploited.
Is it their lies that make you feel hurt? What do you think is motivating them at this point?
It's ok for you to need and ask for the space back.
Trust your friends' resilience and strength, even if they don't trust their own.
Set a deadline, kindly and firmly, and operate with the expectation that the deadline will be met.