Hi Mamma3, welcome. You're in the right place for support -- parenting children with BPD type behaviors is not well understood by others, so I hope this site can be a place where you can find relief and don't have to "explain" to others why your family is different.
Your post stood out to me here:
2 weeks ago he entered a treatment facility’s 7 week in patient program that specializes in BPD and addictions.
Does he seem to be accepting of the reasons why he's there (versus "pretending he doesn't have any problems") and compliant with the program? Did he get an official diagnosis of BPD at the facility, and if so, how is he handling that?
Honestly that sounds positive, if he is in a dual diagnosis facility. Many pwBPD reject diagnoses and treatments due to deep shame. I hope that's giving you and your other kids a breather. Can I ask, how old are your daughters? Younger than him? And were all 3 living at home before he went to treatment?
Write back whenever works for you, and hope you get some peace for a few weeks...
kells76