Hi
LD 
I join
Manifest32 in welcoming you to BPD Family and I echo what she says here:
It’s fantastic that he is sharing with you and tells you that he knows he can trust you.
He's triggered when he makes "mistakes" but knows he can count on you to listen without judgment, so important when supporting a pwBPD (person with BPD). I'm glad he wasn't hurt in the accident and you're right, the details can wait for another day.
You have come to the right place for encouragement, support, and tips; we get it
You're on the right track, arranging counseling for yourself, looking for a support group, posting here. We don't have all the answers, but we all support each other here, without judgment. You don't have to do this alone.
Please share more, as you are comfortable, and ask any questions you like. We are here for you.
Again, welcome!
~ OH