Many members here find that DBT skills are the best way to avoid conflict when talking to BPD relatives - and since they're relatively vague mindfulness
then they often work equally well even with other disorders or anyone you're afraid is going to tear your head off. (I'm not their greatest proponent admittedly, but I'd be remiss if I didn't say I'm in a minority)
Marsha Linehan has a number of videos on Youtube, it would take months to watch them all - but they pretty much all deal with BPD and DBT skills to manage it - skills that ideally both the patient and the caregiver learn (I'd say half the caregivers I know IRL have managed to get their loved one to learn some basic DBT, half have not) -
https://www.youtube.com/watch?v=OTG7YEWkJFI is not a bad start. Her videos/texts make up the bulk of the "Family Connections" course that people will also mention.
I'm glad to hear that he's already 8, and the time when you're able to deal a little more plainly with him is now within easy view - don't lose hope, your marathon race has a visible finish line
